Дисертації: "Strength of the cutting"

1

Molinaro, Marco. "Understanding the Strength of General-Purpose Cutting Planes." Research Showcase @ CMU, 2013. http://repository.cmu.edu/dissertations/257.

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Cutting planes for a mixed-integer program are linear inequalities which are satisfied by all feasible solutions of the latter. These are fundamental objects in mixed-integer programming that are critical for solving large-scale problems in practice. One of the main challenge in employing them is that there are limitless possibilities for generating cutting planes; the selection of the strongest ones is crucial for their effective use. In this thesis, we provide a principled study of the strength of generalpurpose cutting planes, giving a better understanding of the relationship between the different families of cuts available and analyzing the properties and limitations of our current methods for deriving cuts. We start by analyzing the strength of disjunctive cuts that generalize the ubiquitous split cuts. We first provide a complete picture of the containment relationship of the split closure, second split closure, cross closure, crooked cross closure and tbranch split closure. In particular, we show that rank-2 split cuts and crooked cross cuts are neither implied by cross cuts, which points out the limitations of the latter; these results answer questions left open in [56, 65]. Moreover, given the prominent role of relaxations and their computational advantages, we explore how strong are cross cuts obtained from basic and 2-row relaxations. Unfortunately we show that not all cross cuts can be obtained as cuts based on these relaxation, answering a question left open in [56]. One positive message from this result, though, is that cross cuts do not suffer from the limitations of these relaxations. Our second contribution is the introduction of a probabilistic model for comparing the strength of families of cuts for the continuous relaxation. We employ this model to compare the important split and triangle cuts, obtaining results that provide improved information about their behavior. More precisely, while previous works indicated that triangle cuts should be much stronger than split cuts, we provide the first theoretical support for the effect that is observed in practice: for most instances, these cuts have the same strength. In our third contribution, we study the multi-dimensional infinite relaxation introduced by Gomory and Johnson in the late 60’s, which has been an important tool for analyzing and obtaining insights on cutting planes. The celebrated Gomory- Johnson’s 2-Slope Theorem gives a sufficient condition for a cut to be facet defining from the 1-row infinite relaxation. We provide an extension of this result for the k-row case, for arbitrary k, which we call the (k + 1)-Slope Theorem. Despite increasing interest in understanding the multi-row case, no such extension was known prior to our work. This result, together with the relevance of 2-slope functions for the 1-dimensional case, indicates that (k + 1)-slope functions might lead to strong cuts in practice. In our fourth contribution, we consider cuts that generalize Gomory fractional cuts but take into account upper bounds imposed on the variables. More specifically, we revisit the lopsided cuts obtained recently by Balas and Qualizza via a disjunctive procedure. We give a geometric interpretation of these cuts, viewing them as cuts for the infinite relaxation that are strengthened by a geometric lifting procedure. Using this perspective, we are able to generalize these cuts to obtain a family of cuts which has on one end the GMI cut, and on the other end the lopsided cuts. We show that all these cuts are “new”, namely they are all facets of the infinite relaxation with upper bounded basic variable. We conclude by presenting preliminary experimental results, which unfortunately shows that these cuts decrease in importance as they move away from the GMI inequality, complementing the experimental results from Balas and Qualizza. In our final contribution, we further explore properties and characterizations of split cuts, focusing on a general model of mixed-integer corner relaxation. The backbone of this work is a description of the split cuts for this relaxation from the perspective of cut-generating functions; this essentially establishes the equivalence of split cuts and (a generalization of) the k-cuts [50]. As our previous result, this characterization is obtained using the geometric lifting idea, illustrating its flexibility as a tool for analyzing cuts. As a consequence, we show that every split cut for a corner relaxation is the restriction of a split cut for the mixed-integer infinite relaxation, which further indicates the universality of the latter. As another consequence, we construct a pure-integer set with arbitrarily weak split closure, giving a pure-integer counterpart of the mixed-integer construction from [27].

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2

Öhman, Felix. "Comparing the Effectiveness of Punching to Laser Cutting in UltraHigh Strength Steel." Thesis, KTH, Materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298429.

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This study examines the efficiency of punching compared to laser cutting in sheets of Ultra High Strength Steel (UHSS). The study was conducted to determine which process is more efficient with respect to sheet thickness, where the quality of the cut edge is also taken into consideration of whether punching is recommended over laser cutting. The need for information surrounding punching in UHSS will grow as UHSS becomes more common. A simple screener, with dimensions of 1x1 m, with 169 holes, Ø=15 mm, was the sample shape used to test and compare punching to laser cutting. Simulations were made of punching two sheets of Hardox® 500 Tuf with a thickness of 4 mm respectively 5 mm. The laser cutting was also simulated, were a sheet thickness of 4,5,6 and 8 mm was tested, were both a 6 kW laser and a 10 kW laser were used. The lasers use O2 as its high-pressure gas. The punching time was calculated using parameters used for material properties in between S355 and a stainless steel, as it was thought that the punching speed more or less stays the same with varying materials. The cutting time for laser is barely affected by alloying elements and so the cutting time for Hardox® 500 Tuf is estimated to be that of the cutting time of S355. The simulations of punching, laser cutting, and the schematic of the sample screener was done by the company Weland AB. No physical punching was done due to a lack of proper tooling. The simulations of both punching and laser cutting resulted in punching being seven to eight times faster than laser cutting. But due to the extreme properties of Hardox® 500 Tuf, the cut edge of the punched sheets are speculated to be inferior and not suitable for typical wear plate applications. It istherefore recommended to laser cut Hardox 500® Tuf, until further research is done.
Denna studie undersöker effektiviteten av stansning jämfört med laserskärning i plåt av Ultra High Strength Steel (UHSS). Studien genomfördes för att bestämma vilken process som är effektivare med avseende på plåttjocklek, där kvaliteten på den skurna kanten också tas i beaktning vare sig stansning rekommenderas över laserskärning. Behovet av information kring stansning i UHSS kommer att öka i och med att UHSS blir vanligare. En enkel sikt, med måtten 1x1 m, med 169 hål, Ø = 15 mm, var utformningen av plåten som användes för att testa och jämföra stansning med laserskärning. Simuleringar av att stansa två plåtar av Hardox® 500 Tuf gjordes, med en tjocklek av 4 mm respektive 5 mm. Laserskärningen simulerades också, där en plåttjocklek på 4,5,6 och 8 mm testades, där både en 6 kW laser och en 10 kW laser simulerades. Lasrarna använder O2 som högtrycksgas. Stanstiden beräknades med hjälp av parametrar som används för material med materialegenskaper mellan S355 och rostfritt stål, eftersom man ansåg att stansningshastigheten mer eller mindre förblir densamma för olika material. Skärtiden för laser påverkas knappt av legeringsämnen och därför beräknas skärtiden för Hardox® 500 Tuf vara samma som skärtiden för S355. Simuleringarna av stansning och laserskärning samt ritningen för provets utformning, gjordes av företaget Weland AB. Ingen fysisk stansning gjordes på grund av brist på rätt verktyg. Simuleringarna av både stansning och laserskärning resulterade i att stansning var sju till åtta gånger snabbare än laserskärning. Men på grund av de extrema egenskaperna hos Hardox® 500 Tuf, spekuleras det att kvaliteten på den skurna kanten hos de stansade plåtarna vara undermålig, och lämpar sig då ej för typiska slitplåtstillämpningar. Det rekommenderas därför att laserskära Hardox 500® Tuf tills ytterligare forskning har utförts.

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3

Medvedeva, Anna. "Performance of advanced tool steels for cutting tool bodies." Doctoral thesis, Karlstads universitet, Avdelningen för maskin- och materialteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-5630.

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Performance of indexable insert cutting tools is not only about the performance of cutting inserts. It is also about the cutting tool body, which has to provide a secure and accurate insert positioning as well as its quick and easy handling under severe working conditions. The common damage mechanisms of cutting tool bodies are fatigue and plastic deformation. Cutting tools undergo high dynamic stresses going in and out cutting engagement; as a result, an adequate level of fatigue strength is the essential steel property. Working temperatures of tool bodies in the insert pocket can reach up to 600°C, why the tool steel requires high softening resistance to avoid plastic deformation. Machinability is also essential, as machining of the steel represents a large fraction of the production cost of a cutting tool. The overall aim of the study is to improve the tool body performance by use of an advanced steel grade with an optimized combination of all the demanding properties. Due to the high-temperature conditions, the thesis concerns mostly hot-work tool steels increasing also the general knowledge of their microstructure, mechanical properties and machinability. Knowing the positive effect of sulphur on machinability of steels, the first step was to indentify a certain limit of the sulphur addition, which would not reduce the fatigue strength of the tool body below an acceptable level. In tool bodies, where the demand on surface roughness was low and a geometrical stress concentrator was present, the addition of sulphur could be up to 0.09 wt%. Fatigue performance of the cutting tools to a large extent depended on the steel resistance to stress relaxation under high dynamic loading and elevated temperatures. The stress relaxation behaviour, material substructure and dislocation characteristics in low-alloyed and hot-work tool steels were studied using X-ray diffraction under thermal and mechanical loading. Different tool steels exhibited different stress relaxation resistance depending on their microstructure, temper resistance and working temperature. Hot-work tool steels showed to be more preferable to low-alloyed tool steels because of their ability to inhibit the rearrangement and annihilation of induced dislocations. High-temperature softening resistance of the hot-work tool steels was investigated during high-temperature hold-times and isothermal fatigue and discussed with respect to their microstructure. Carbide morphology and precipitation were determined using scanning and transmission electron microscopy. Machinability of a prehardened hot-work tool steel of varying nickel content from 1 to 5 wt% was investigated in end milling and drilling operations. Machining the higher nickel containing steels resulted in longer tool life and generated lower cutting forces and tool/workpiece interface temperature. The difference in machinability of the steels was discussed in terms of their microstructure and mechanical properties.

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Ray, Nathan. "Correlation between machining monitoring signals, cutting tool wear and surface integrity on high strength titanium alloys." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/20660/.

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It is widely accepted that tool wear has a direct impact on a machining process, playing a key part in surface integrity, part quality, and therefore, process efficiency. By establishing the state of a tool during a machining process, it should be possible to estimate both the surface properties and the optimal process parameters, while allowing intelligent predictions about the future state of the process to be made; thus ultimately reducing unexpected component damage. This thesis intends to address the problem of tool wear prediction during machining where wear rates vary between components; for instance, due to the relatively large size of the component forging and, therefore, inherent material variations when compared to existing research. In this case, the industrial partner, Safran Landing Systems, is interested in the ability to predict tool wear during the finish milling of large, curved, titanium components, despite differing material properties and, therefore, tool wear rates. This thesis is split into four key parts, the first of which describes in detail the formulation and implementation of an experimental procedure, intended to provide a working set of industrially representative monitoring data that can be used throughout the remainder of the thesis. This part includes development of a relevant machining strategy, material specimen extraction, sensor selection and placement, and 3D tool geometry measurement, all of which have been completed at industrial partners facilities. It finishes with a preliminary investigation into the data collected during the machining process from the tools, material specimens, and sensors placed in close proximity to the cutting zone. The second, third, and fourth parts follow logically from one-another, beginning with a state classification problem, and ending with a full dynamic model prediction of wear during the machining of large landing gear components; this method, however, is applicable to many other machining scenarios using the new technique applied in this thesis. The state classification chapter is a necessary first step in developing a predictive model as is aims to prove the data is indeed separable based upon the generating wear state. Once confirmed, given the sequential nature of tool wear, the order of observations can be included in the modelling, in an attempt to improve classification accuracy. This forms the basis of the state tracking chapter, and leads naturally into the full dynamic model prediction in the final part. This is a promising result for the machining community, as process monitoring often relies on operator expertise to detect wear rate fluctuations and, in turn, results in over-conservative tool usage limits, adding time and expense to many complex machining processes. It also presents the opportunity to predict part quality through pre-existing relationships between the acquired signals and material surface finish - correlations which are explored and presented as part of this thesis. The solution to predicting a varying wear rate within a harsh machining environment introduced in this thesis is based around the application of a Gaussian process (GP) NARX (Nonlinear Auto-Regressive with eXogenous inputs) model borrowed from the machine learning prediction and, more recently, structural health monitoring (SHM) communities. The GP-NARX approach is found to be well suited to the application of wear prediction during machining, and forms a promising contribution to the development of autonomous manufacturing processes.

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Farrapo, Samily de Paulo. "Glycerines gross and semipurified on cutting power quails." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15952.

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FundaÃÃo de Amparo Ã Pesquisa do Estado do CearÃ
Objetivou-se avaliar o uso das glicerinas mista e bruta na alimentaÃÃo de codornas de corte. Foram executados dois experimentos, sendo um de digestibilidade para determinar os valores energÃticos da glicerina vegetal bruta e da mista semipurificada. No segundo experimento avaliou-se o desempenho, caracterÃsticas da carcaÃa e da carne de codornas de corte recebendo diferentes nÃveis de inclusÃo dessas glicerinas nas dietas. No ensaio de digestibilidade utilizou-se 180 codornas de corte, dos 14 aos 21 de idade, alojadas em gaiolas para estudos metabÃlicos, distribuÃdas em delineamento inteiramente casualizado em esquema fatorial 2x2+1, sendo 2 nÃveis de substituiÃÃo da raÃÃo referÃncia pela glicerina (10 e 20%), dois tipos de glicerinas (vegetal e mista), mais a raÃÃo referÃncia, totalizando 5 tratamentos com 6 repetiÃÃes de 6 aves. O perÃodo experimental foi de oito dias, sendo quatro para a adaptaÃÃo e quatro para coleta total de excretas. A glicerina vegetal bruta apresentou maior energia metabolizÃvel aparente corrigida pelo balanÃo do nitrogÃnio com base na MS (EMAn kcal/kgMS), como na MN (EMAn kcal/kgMN), 5.195 e 4.759, contra 3.884 e 3.472 para a glicerina mista semipurificada, para os valores energÃticos, respectivamente. No segundo experimento utilizou-se 432 codornas de corte de 1 a 42 dias de idade, distribuÃdas em delineamento inteiramente casualizado em esquema fatorial 2x4+1, sendo 2 tipos de glicerinas (vegetal e mista), 4 nÃveis de inclusÃo de glicerinas nas dietas (5, 10, 15 e 20%), mais a raÃÃo controle, sem inclusÃo de glicerina, totalizando 9 tratamentos com 4 repetiÃÃes de 12 aves. Aos 42 dias as aves passaram por jejum sÃlido de oito horas, para o abate, sendo duas aves de cada repetiÃÃo separadas dentro do peso mÃdio, para posteriores anÃlises. Avaliou- se o consumo de raÃÃo, ganho de peso, conversÃo alimentar, rendimento de carcaÃa, de cortes (peito e coxa+sobrecoxa), teor de gordura abdominal, biometria dos ÃrgÃos (fÃgado, coraÃÃo e moela), amÃnia volÃtil, umidade e PH da cama, bem como as caracterÃsticas fÃsicas e sensoriais da carne. Os dados foram submetidos Ã anÃlise de variÃncia e os nÃveis de inclusÃo das glicerinas, foram desdobrados em polinÃmios. Para comparaÃÃo em relaÃÃo ao tratamento controle, foi utilizado o teste de Dunnett (5%). Observou-se diferenÃa para o desempenho, onde a glicerina mista proporcionou maiores resultados para consumo de raÃÃo em todos os perÃodos analisados, bem como na conversÃo alimentar de 1 a 21 dias e de 1 a 42 dias de idade das codornas. NÃo foi observada diferenÃa entre as glicerinas utilizadas para a amÃnia volÃtil, enquanto entre os nÃveis de inclusÃo das glicerinas houve efeito linear crescente para essa variÃvel Ã medida que se adicionou qualquer das glicerinas nas raÃÃes. O pH da cama foi superior ao se utilizar qualquer nÃvel de inclusÃo da glicerina vegetal quando comparado ao tratamento controle, bem como a partir de 10% de inclusÃo os valores de pH sÃo maiores ao se utilizar a glicerina vegetal e nÃo a mista. Nenhum dos fatores analisados interferiu no teor de umidade da cama. NÃo foram observadas diferenÃas para o rendimento, jÃ a gordura abdominal mostrou-se maior nas aves que consumiram raÃÃo contendo glicerina vegetal. Para as caracterÃsticas fÃsicas da carne considerou-se a perda de peso por cocÃÃo, forÃa de cisalhamento e capacidade de retenÃÃo de Ãgua, onde os dados para os nÃveis de inclusÃo das glicerinas foram desdobrados em polinÃmios, enquanto que para as glicerinas usado o Teste F. JÃ para as caracterÃsticas sensoriais, aroma, cor, sabor e avaliaÃÃo global, as mÃdias foram comparadas pelo teste de Ducan a 5%. O uso de glicerina vegetal ou mista nÃo interferiu nas caracterÃsticas sensoriais da carne de codorna (P>0,05), podendo ser usada em atÃ 20% de inclusÃo nas raÃÃes. Para as caracterÃsticas fÃsicas houve diferenÃa (P<0,05) para forÃa e cisalhamento sendo os nÃveis 12,5% da GMS e 12,78% da GVB os que apesentaram melhores resultados. Para PPC e CRA nÃo houve diferenÃa (P> 0,05) entre os tratamentos analisados. Conclui-se que as duas glicerinas possuem potencial para serem utilizadas atÃ 20% na alimentaÃÃo de codornas, sem prejudicar o ganho de peso, o rendimento e a qualidade da cama, sendo a glicerina bruta a que apresenta maior quantidade de energia. No entanto, 13% de inclusÃo de glicerina nas raÃÃes de codorna proporciona uma carne mais suculenta.
The objective was to evaluate the use of mixed and gross glycerines on slaughter quail. Two experiments were performed, one of digestibility to determine the energy values of crude vegetable glycerin and semipurified mixed. The second experiment evaluated the performance, carcass characteristics and meat quail meat receiving different levels of inclusion in the diets of these glycerides. In the digestibility assay was used 180 quails, from 14 to 21 of age, housed in cages for metabolic studies, distributed in a completely randomized design in a factorial 2x2 + 1, 2 ration of replacement reference levels for glycerin (10 and 20%), two types of glycerides (crop and mixed), the more the reference diet, totaling five treatments with 6 replications of 6 birds. The experiment lasted eight days, four for adaptation and four for excreta collection. Gross vegetable glycerin had a higher apparent metabolizable energy corrected by nitrogen balance based on MS (AMEn kcal / kgMS) as the MN (AMEn kcal / kgMN), 5,195 and 4,759, against 3,884 and 3,472 for the semipurified mixed glycerin to the energy values, respectively. In the second experiment we used 432 quails 1- 42 days old, distributed in a completely randomized design in a factorial 2x4 + 1, 2 types of glycerides (vegetable and mixed), 4 glycerines inclusion levels in diets (5, 10, 15 and 20%) over control diet without the addition of glycerin, a total of 9 treatment with 4 replications of 12 birds. At 42 days the birds have undergone solid fasting for eight hours for slaughter, two birds of each separate repetition within the medium weight, for further analysis. It were evaluate the feed intake, weight gain, feed conversion, carcass yield, cuts (breast and thigh + drumstick), abdominal fat, biometry of the organs (liver, heart and gizzard), volatile ammonia, moisture and PH of the bed, as well as physical and sensory characteristics of meat. Data were subjected to analysis of variance and levels of inclusion of glycerides, they were deployed in polynomials. For comparison compared to the control treatment was performed using the Dunnett's test (5%). Difference was observed for performance, where the mixed glycerol provided greater results for feed intake in all periods analyzed, as well as feed conversion 1-21 days and 1-42 days of age of quail. No difference was observed between the glycerides used for volatile ammonia, while between the levels of inclusion of glycerines there was increasing linear effect for this variable as they added either glycerines in feed. The pH was superior to the bed using any inclusion level of vegetable glycerin compared to the control treatment and from 10% to include the pH values are higher when using the vegetable glycerine and not mixed. None of the analyzed factors interfered with the moisture content of the bed. There were no difference for yield, since abdominal fat was higher in birds fed diet containing vegetable glycerin. For the physical characteristics of the meat considered the weight loss for cooking, shear strength and water holding capacity, where data for inclusion levels of glycerides were deployed in polynomials, while for the glycerides used Test F . As for the sensory characteristics, aroma, color, flavor and overall evaluation, the means were compared by 5% Duncan test. The use of vegetable glycerin mixed or no effect on the sensory characteristics of quail meat (P>0.05), can be used in up to 20% inclusion in diets. For the physical difference (P <0.05) for strength and shear levels being 12.5% of GMS and 12.78% of GVB apesentaram that the best results. CRA for PPC and there was no difference (P> 0.05) between treatments analyzed. It follows that the two glycerides have potential to be used up to 20% in the feed quail, without harming the weight gain, the yield and quality of the bed, and the crude glycerin presents the highest amount of energy. However, 13% inclusion of glycerin in quail rations provides a more succulent meat.

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Stenberg, Thomas. "Fatigue properties of cut and welded high strength steels : Quality aspects in design and production." Doctoral thesis, KTH, Lättkonstruktioner, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-188225.

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This doctoral thesis concerns fatigue of welded structures. Welding is one of the world’s most common joining methods and it is frequently used in several structural applications in many fields. Some examples are construction vehicles, loader cranes, trucks, busses, forestry and agricultural machines, bridges and ships. Since these structures are subjected to repeated loading, fatigue is the most common cause of failure. A novel numerical algorithm has been developed which assesses the welded surface and calculates and quantifies weld quality parameters and the presence of defects which are critical in fatigue applications. The algorithm is designed for implementation in serial production. It will provide robust and reliable feedback on the quality being produced, which is essential if high strength steels are utilized. Two welding procedures which can increase the weld quality in as welded conditions have been assessed. These procedures utilize welding in different positions and pendling techniques, which can be accomplished using the existing welding equipment. It was found that by using these methods, the fatigue strength can be increased compared to normal weld quality. Furthermore, two fatigue assessment methods ability to account for increased weld quality in low cycle and high cycle fatigue applications has been studied. One of these methods showed sufficient accuracy in predicting the fatigue strength with small scatter and also account for increased weld quality. When implementing thinner high strength steels, the overall stress level in the structure increase. Therefore, other locations such as the steel cut edges may become critical for fatigue failure unless they are not designed and manufactured with the same quality as the welded joint. The influence of surface quality on cut edges was studied and the fatigue strength was estimated using international standards and a fatigue strength model for cut edges.

QC 20160613

WIQ
LIGHTSTRUCT
ONWELD

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Gram, Michael D. "Fineblanking of High Strength Steels: Control of Materials Properties for Tool Life." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1280869210.

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Bi, Wu. "Racking Strength of Paperboard Based Sheathing Materials." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1091059928.

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Stater, Lydia M. "Female Friendship: Strength Found Through Support." Kent State University Honors College / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1525691709141172.

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Буковський, Олег Миколайович. "Підвищення ефективності обробки отворів малих розмірів в умовах автоматизованого виробництва". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/25648.

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Магістерська атестаційна робота на тему: «Підвищення ефективності обробки отворів малих розмірів в умовах автоматизованого виробництва» складається із 109 аркушів. До неї входять: 18 рисунків, 31 таблиця, 3 додатки. В роботі використано 52 бібліографічні найменування. Завданням даної роботи є розробка системи підвищення ефективності обробки отворів малих розмірів в умовах автоматизованого виробництва. Проаналізовано існуючі методи підвищення ефективності обробки отворів малих розмірів в умовах автоматизованого виробництва, розглянуто методи їх формоутворення, здійснено теоретичне дослідження особливостей процесу різання при свердлінні отворів, встановлено вплив швидкості різання, властивостей оброблюваного матеріалу, діаметра свердла, подачі та температури різання на ефективність обробки отворів малих розмірів. В результаті досліджень вирішено розробити автоматизовану систему підвищення ефективності обробки отворів малих розмірів, яка базується на вимірюванні сил різання та крутного моменту процесу свердління. Для її реалізації створено математичну модель, принципову схему роботи, побудовано алгоритм її роботи та створено необхідне програмне забезпечення. Здійснено дослідження підвищення ефективності обробки отворів малих розмірів з допомогою повного факторного експерименту. Результати даної роботи можуть бути використані державними підприємствами задля підвищення ефективності обробки отворів малих розмірів в умовах автоматизованого виробництва шляхом контролю процесу різання.
Master's attestation work on the topic: "Improving the efficiency of processing apertures of small sizes in the conditions of automated production" consists of 109 sheets. It includes 18 pictures, 30 tables, 3 attachments. 52 bibliographic titles were used in the work. The task of this work is to develop a system for improving the processing efficiency of small-sized apertures in the conditions of automated production. The existing methods of increasing the efficiency of processing small-sized apertures in the conditions of automated production are analyzed, the methods of their forming are considered, the theoretical study of the features of the cutting process during drilling of apertures has been carried out, the influence of cutting speed, properties of the treated material, the diameter of the drill, the filing and the temperature of cutting on the efficiency of processing the apertures of small sizes. As a result of the research, it was decided to develop an automated system for improving the efficiency of small-sized aperture processing, which is based on measuring the cutting forces and torque of the drilling process. For its realization a mathematical model, a basic scheme of work was created, an algorithm of its work was created and the necessary software was created. The research of increase of efficiency of processing of apertures of small sizes with the help of a full factor experiment has been carried out. The results of this work can be used by state-owned enterprises to improve the efficiency of processing small-sized apertures in the conditions of automated production by controlling the cutting process.

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Diaz, Infante Hernandez David Alberto. "Prediction and Prevention of Edge Fracture in Forming of AHSS." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563371149338966.

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12

Haddad, Fares. "Etude de l'influence de la structure métallurgique sur l'usinabilité des aciers à hautes caractéristiques mécaniques." Thesis, Paris, HESAM, 2020. http://www.theses.fr/2020HESAE003.

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Durant la dernière décennie, le développement de nouvelles nuances d'acier à très haute résistance a connu un essor, en particulier dans l’automobile. Les acteurs de ce secteur ont pour objectif de produire des véhicules plus légers, plus performants, plus économes en carburant et garantissant un plus haut niveau de sécurité pour les passagers. De nouvelles nuances ou de nouvelles structures sont apparues sur le marché : plus résistants avec un meilleur compromis résistance/ductilité. Cependant cette élévation des propriétés mécaniques se fait le plus souvent au détriment de l’usinabilité des aciers.Les résultats de travaux antérieurs ont motivé une étude poussée qui porte sur l’influence de la structure métallique sur l’usinabilité des aciers. Le travail compare le comportement d’un aciers bas-carbone obtenue par refroidissement contrôlé à celui d’une nuance conventionnelle à l’état trempé revenue et à l’état bainitique. Les conditions thermomécaniques rencontrées à l’interface outil/copeau lors de l’usinage sont caractérisées par mesure des efforts de coupe et investigation de la morphologie et de la microstructure des copeaux. La durée de vie des outils coupants est quantifiée et les différents modes d’usure sont caractérisés
During the past decade, the automotive industry is increasingly relying on new grades of high strength steels. Companies involved in this sector aim to produce lighter, more effective vehicles that are both fuel-efficient and guarantee a high level of safety for its passengers. New structures have emerged on the market presenting an opportune correlation between high mechanical resistance and ductility. However, this increase in mechanical properties is most often achieved at the expense of the machinability of steels in question.The results of previous works have motivated a detailed study that focuses on the influence of the metallic structure on the machinability of steels. The work compares the behavior of low-carbon steels obtained by controlled cooling with that of a conventional steel in both the quenched and tempered state and the bainitic state. The thermomechanical conditions at the tool / chip interface during cutting are identified by measuring the cutting forces and investigating the chips morphology and microstructure. The cutting-tool life expectancy is quantified and the different modes of insert wear are studied

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13

Wirnsperger, Franz. "Laserstrahltiefschweißen hochfester Feinkornbaustähle in der Serienproduktion: Experimentelle Bewertung werkstoffbedingter und fertigungstechnischer Einflüsse auf die Prozess- und Verbindungsstabilität." Universitätsverlag Chemnitz, 2020. https://monarch.qucosa.de/id/qucosa%3A71721.

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In der serienmäßigen Verarbeitung von hochfesten Feinkornbaustählen zeigte sich, dass verschiedene Stähle gleicher Festigkeitsklasse zu stark unterschiedlichen Schweißergebnissen beim Laserstrahltiefschweißprozess führen können. Die materialbedingten Einflüsse auf das Schmelzbadverhalten sind bisher in keiner bekannten Forschungsarbeit untersucht worden. Diese Arbeit erweitert die bisherige Forschung mit neuen Erkenntnissen aus umfangreichen Materialanalysen und Schweißversuchen. Dadurch wurde es möglich, ein ganzheitliches Erklärungsmodell der materialbedingten Einflüsse beim Laserstrahltiefschweißprozess zu beschreiben. Diese Arbeit fokussierte sich einerseits auf die Analyse der chemischen Zusammensetzung der Grundmaterialien und die Auswirkungen der Legierungselemente auf die Schweißnahtvorbereitung in Kombination mit dem Vorprozess Laserstrahlbrennschneiden. Andererseits wurde gezielt die Auswirkung der chemischen Grundmaterialzusammensetzung auf das Schmelzbadverhalten im Laserstrahltiefschweißprozess untersucht. Dabei wurden die Blechstärken so variiert, dass durchgeschweißte und nicht durchgeschweißte I-Naht-Verbindungen, geschweißt unter konstanten Schweißbedingungen, analysiert werden konnten. Die Schweißparameter und der Hilfsstoffeinsatz wurden dabei konstant gehalten, sodass Vergleichsanalysen der Schweißergebnisse möglich waren. Bei durchgeschweißten Stößen wurde die Schmelzbadoberfläche, aber auch die Schmelzbadunterseite per Hochgeschwindigkeitskamera inkl. Laserlichtfilter analysiert. Bei nicht durchgeschweißten Stößen wurde die Wirkung der verschiedenen Schnittkantenzustände auf das Einschweißverhalten und die Einbrandgeometrie an mehr als 100 Makroschliffen untersucht. Die Untersuchungen zeigten, dass die Art der Schnittkantenbehandlung nach dem Laserstrahlbrennschneidprozess materialbedingt zu unterschiedlichen Schnittkantenzuständen führt. Diese können in weiterer Folge die Schweißergebnisse stark beeinflussen. Auch bei mechanisch bearbeiteten Schweißnahtvorbereitungen wurden grundwerkstoffbedingte Unterschiede in der Einbrandform und im Erstarrungsgefüge nachgewiesen. Unbehandelte und somit schnittoxidbehaftete Schnittkanten bzw. auch Schweißnahtvorbereitungen mit manuell aufgetragenem SiO2 führen zu einer Stabilisierung der Dampfkapillare und erhöhen die Einschweißtiefe signifikant. Die positive Wirkung von Oxiden, welche direkt in der Schweißfuge dem Schmelzbad zugeführt werden, wurden mit den experimentellen Versuchen in dieser Arbeit erstmals nachgewiesen. Bei den gewählten Schweißparametersätzen stellen die Oxide in der Schweißfuge die dominierende Einflussmöglichkeit beim Laserstrahltiefschweißprozess dar. Vergleiche der mechanisch-technologischen Verbindungseigenschaften bei unterschiedlichen Schnittkantenzuständen und Schweißversuche mit unterschiedlichen Schutzgaszusammensetzungen zeigten die Auswirkungen der verschiedenen Fugenvorbereitungen auf die Schweißergebnisse. Durch die Kombination der bisherigen Erkenntnisse aus der Forschung mit den neu gewonnenen Erkenntnissen aus dieser Arbeit, konnte ein ganzheitliches Erklärungsmodell aufgestellt werden, das die Einflüsse der Grundmaterialzusammensetzung entlang der Prozesskette beschreibt und die materialabhängigen Unterschiede der Schweißergebnisse aus dem Laserstrahltiefschweißprozess nachvollziehbar macht. Die Erkenntnisse dieser Arbeit ermöglichen ein erhöhtes Prozessverständnis und zeigen neue Möglichkeiten zur Effizienzsteigerung in der Blechverarbeitungsprozesskette mit Lasertechnologien.:1 Einleitung 2 Zielsetzung 3 Stand der Technik 4 Experimentelles 5 Ergebnisse der experimentellen Untersuchungen 6 Zusammenfassung und Diskussion der Ergebnisse 7 Schlussfolgerungen und Ausblick
In the industrial series processing of high-strength fine grain steels, it was found that different steels of the same strength class can lead to different welding results by the laser beam keyhole welding process. The material-related influences on the molten pool behavior have not yet been investigated in any known research. This research work extends the state of knowledge with new findings from extensive material analysis and welding tests. This new findings made it possible to describe a holistic explanatory model of the material-related influences in the laser beam keyhole welding of high-strength fine grain steels. On the one hand, this work focused on the analysis of the chemical composition of the base materials and the effects of the alloying elements on the weld preparation in combination with the laser cutting process. On the other hand, the effect of the chemical base material composition on the melt pool behavior during laser keyhole welding process was specifically investigated. The welding parameters and the use of filler material were kept constant so that comparative analysis of the welding results was possible. The sheet thicknesses were varied so that full penetration and partly penetration I-seam-butt-welds could be analyzed. While welding full penetration welds, the surface of the molten pool as well as the root of the melt pool was analyzed by a high-speed camera equipped with laser light filter. For the partly penetration welds, the effect of the different cutting edge conditions on the penetration depth and the weld penetration geometry was investigated on more than 100 macro sections. The investigations have shown that the type of cut edge treatment after the laser beam cutting process leads to different cutting edge conditions depending on the material. These different conditions can subsequently strongly influence the welding results. Base-material-related differences in the penetration shape and in the solidification structure were detected in the cross sections even on seams welded on mechanically processed edge preparations. After laser beam cutting, untreated and thus cut-oxide-containing cut edges lead to a stabilization of the keyhole and increase the penetration depth significantly. This effect could also be observed with manually applied SiO2 on the mechanically processed edge preparations before welding. The positive effects of oxides, which are existing directly in the weld preparation groove, were first detected with the experimental investigations during this work. With regard to the selected welding parameter sets, the oxides that are directly on the weld preparation edges are the dominant influence option in the laser beam keyhole welding process. Comparisons of the mechanical-technological joint properties at different cutting edge conditions and welding tests with different protective gas compositions showed the impacts of various joint preparations on the final welding results. By combining previous experience with the results of this work, a holistic explanatory model was developed, which describes the influence of the base material composition along the process chain and makes the material-dependent differences of the welding results of the laser beam keyhole welding process comprehensible. The findings of this work enable a better understanding of the process and show new possibilities for increasing efficiency in the concerned sheet metal processing chain with laser technologies.:1 Einleitung 2 Zielsetzung 3 Stand der Technik 4 Experimentelles 5 Ergebnisse der experimentellen Untersuchungen 6 Zusammenfassung und Diskussion der Ergebnisse 7 Schlussfolgerungen und Ausblick

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14

Oen, Richard James. "Measuring cutting forces on a metal cutting lathe." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182447008.

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15

Oen, Jr Richard James. "Measuring cutting forces on a metal cutting lathe." Ohio University / OhioLINK, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1182447008.

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16

Sircom, Margaret A. "Cutting clear." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ47766.pdf.

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17

Lotfalian, Majid. "Cutting Principles." Sari University of Agricultural Sciences and Natural Resources, 2012. https://slub.qucosa.de/id/qucosa%3A17076.

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This is a chapter of a book that has been published in Persian Language in 2012. Here the physical and static rules of trees are presented and the methods are explained for feeling trees in correct way: balanced trees, low leaning trees, heavy leaning trees, felling of special trees, in steep slopes, releasing hang up trees and using winch.:1. Review of the physical basis of the forces involved in cutting and bucking 1.1. Vector and scalar quantities 1.2. Weight 1.3. Center of gravity 1.4. Fulcrum 1.5. Forces and torque 1.6. Relations between vectors 1.7. Levers 1.7.1. Single and double levers of the first class 1.7.2. Single and double levers of the second class 1.7.3. Single and double levers of the third class 1.8. Efficiency and mechanical advantage 1.9. Work 1.10. Wedge 2. Correct methods in felling trees 2.1. Balanced trees 2.2. Low leaning trees 2.2.1. Felling the low leaning trees in the leaning direction 2.2.2. Felling trees with a low leaning in the side direction of leaning 2.2.3. Felling trees with light leaning in opposite of leaning direction 2.3. Trees with heavy leaning 2.3.1. Felling trees with heavy leaning in leaning direction 2.3.2. Felling trees with heavy leaning in side of leaning direction 2.3.3. Felling trees with heavy leaning in opposite of leaning direction 2.4. Felling of special trees 2.5. Felling of trees in steep slopes 2.6. Release of hang up trees 2.7. Using winch 2.7.1. Felling of trees in leaning direction using winch 2.7.2. Felling of trees in side of leaning direction using winch 2.7.3. Felling of trees in opposite of leaning direction using winch 2.7.4. Safety measures in use of winch
Es handelt sich um ein Kapitel aus einem Buch, das 2012 im persischer Sprache veröffentlicht wurde. Darin werden die physikalischen und statischen Prinzipien von Bäumen dargestellt und die Methoden erklärt, mit denen Bäume korrekt gefällt werden können: aufrechte Bäume, Bäume mit einem leichten und starken Hang, Spezialfällung, Fällung am Steilhang und von Hängern, Einsatz einer Winde.:1. Review of the physical basis of the forces involved in cutting and bucking 1.1. Vector and scalar quantities 1.2. Weight 1.3. Center of gravity 1.4. Fulcrum 1.5. Forces and torque 1.6. Relations between vectors 1.7. Levers 1.7.1. Single and double levers of the first class 1.7.2. Single and double levers of the second class 1.7.3. Single and double levers of the third class 1.8. Efficiency and mechanical advantage 1.9. Work 1.10. Wedge 2. Correct methods in felling trees 2.1. Balanced trees 2.2. Low leaning trees 2.2.1. Felling the low leaning trees in the leaning direction 2.2.2. Felling trees with a low leaning in the side direction of leaning 2.2.3. Felling trees with light leaning in opposite of leaning direction 2.3. Trees with heavy leaning 2.3.1. Felling trees with heavy leaning in leaning direction 2.3.2. Felling trees with heavy leaning in side of leaning direction 2.3.3. Felling trees with heavy leaning in opposite of leaning direction 2.4. Felling of special trees 2.5. Felling of trees in steep slopes 2.6. Release of hang up trees 2.7. Using winch 2.7.1. Felling of trees in leaning direction using winch 2.7.2. Felling of trees in side of leaning direction using winch 2.7.3. Felling of trees in opposite of leaning direction using winch 2.7.4. Safety measures in use of winch

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18

Addala, Srikanth. "Relationship between cutting parameters and bit geometry in rotary cutting." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1553.

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Thesis (M.S.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains x, 71 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 64-68).

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19

MacBeath, Alan. "Ultrasonic bone cutting." Thesis, University of Glasgow, 2006. http://theses.gla.ac.uk/2220/.

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This thesis reports on the design of ultrasonic bone cutting blades and the effect of various cutting parameters such as applied load, blade tip vibration velocity and frequency on cutting speed and temperature, two performance indicators used by orthopaedic clinicians. A range of high gain blades was developed to investigate the correlation between the frequency response predicted by finite element analysis (FEA) and the frequency response measured using an experimental model analysis (EMA) technique. It has been found that FEA frequency predictions are within 1.5% of measured frequencies. FEA has also been used to develop two novel ultrasonic cutting models which allow the effect of blade progression on cutting performance to be investigated. The models have been used to predict the relationship between applied load and cutting speed in single layer and multi-layer materials, and have shown that cutting speed decreases as cortical layer thickness increases, a trend also found from cutting experiments. Ongoing developments to predict temperature from both cutting models have produced a preliminary result which locates regions of maximum cutting temperature. The result influenced the design of blades with modified tip geometries that have been used to reduce cutting temperature. Ultrasonic cutting experiments were performed on bovine bone, two bone substitute materials and various grades of wood. Deep incisions were made for a range of applied loads and cutting speeds to investigate the effect of various cutting parameters on cutting temperature. Ultrasonic cutting has been successfully applied to perform deep incisions in bone whilst maintaining substrate temperature to within critical levels. Two innovative modelling techniques have been used to simulate ultrasonic cutting and demonstrate their potential for revolutionising blade design, and surgical trials.

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20

Toksvig-Larsen, Søren. "On bone cutting." Lund : University Dept. of Orthopedics, 1992. http://books.google.com/books?id=3JBsAAAAMAAJ.

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21

Bass, Matthew L. "Cutting Into Relief." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3416.

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The following is an examination of the ideas and decisions that went into an art exhibition held in gallery 303 of the Harris Fine Art Center February 1-13, 2013. The exhibition explores the relationships of the artwork, artist, viewer, and space. The catalyst for the above mentioned exploration is a process of making art using linoleum relief printing. The subject of the artwork is an in-depth examination of the material and printing process. It is my contention that such a close look at the art making process reveals the attitudes and decisions that we make with any human endeavor.

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22

Jalap, Joakim. "Cutting the Sentiment." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-153965.

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In this thesis we have adapted a graph method used by Pang and Lee tonot use any machine learning, in order to use it for near real time sentimentanalysis. The machine learning step has been replaced with a novel approach toconstruct one positive document and one negative document respectively. These are positive and negative with respect to the features deemed most important inthe corpus and said features are extracted using an algorithm devised by Cataldiet al. This enables us to replace the machine learning step in Pang and Lees algorithm with a semantic matching between the documents to classify and the constructed documents.We find that TF-IDF is not a suitable measurement for discerning sentiment,and we also note some general difficulties in using the minimum cut algorithm ona near complete graph relating to the instability of said algorithm. The methodis found to give better results for the negative reviews than for the positive, and some possible reasons for this is also discussed.
I detta examensarbete har vi anpassat en grafmetod som användes av Pang och Lee till att inte använda maskininlärningstekniker, så att den kan användas för “near real time” sentimentanalys. Maskininlärningssteget har ersatts men en nyskapande metod för att konstruera ett positivt respaktive ett negativt dokument. Dessa är positiva respektive negative med avseende på de substantiv som bedöms vara viktigast i korpuset, och nämnda substantiv extraheras meden algoritm utvecklad av Cataldi et al. Detta gör att vi kan ersätta maskininlärningsstegeti Pand och Lees algoritm med en semantisk matchning mellan dokumenten som skall klassificeras och de konstruerade dokumenten.Vi finner att TF-IDF inte är en lämplig metod för att urskilja sentiment och vi gör också en del allmänna observationer angående svårigheter med att använda minimala-snittet-metoder i en nästan komplett graf. Metoden som beskrivs ger bättre resultat för negativa recensioner än för positiva och några möjliga skäl till detta diskuteras också.

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23

Anderson, I. "A study of the dynamic cutting characteristics of roadheader cutting heads." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315535.

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24

Lätzer, Michael. "Füge- und Übertragungsverhalten torsionsbelasteter Stahl-Aluminium-Rändelpressverbindungen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-200348.

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Die vorliegende Dissertation beschäftigt sich mit analytischen, numerischen und experimentellen Grundlagenuntersuchungen zum Füge- und zum Übertragungsverhalten einer reibformschlüssigen Stahl-Aluminium-Rändelpressverbindung. Die Besonderheit dieser Verbindung besteht darin, dass eine mit einer Rändelung und Übermaß versehene harte Stahlwelle in eine weiche Aluminiumnabe mit kreisrunder Bohrung längseingepresst wird. Die maßgebende Größe für den Fügevorgang ist der Fasenwinkel der Welle φ. Der Nabenwerkstoff wird hierbei in Abhängigkeit des Fasenwinkels der Welle φ umgeformt beziehungsweise herausgeschnitten. Mit Hilfe der relativen Festigkeit R F , welche das Verhältnis von maximaler Lösekraft F l, max zu maximaler Fügekraft F f, max repräsentiert, wurde ein Gütekennwert zur gezielten Auswahl von Stahl-Aluminium-Rändelpressverbindungen hinsichtlich der axialen Übertragungsfähigkeit abgeleitet. Die Charakterisierung der experimentell ermittelten Torsionsmoment - Verdrehwinkel - Kurven ergab zur Auslegung die Bereiche Auslegungs- und Versagenskriterium. Das maximal übertragbare Torsionsmoment wird beim sogenannten Versagenskriterium τ S durch das Abscheren der Rändel in der Nabe erreicht. In Analogie zum Füge- und zum Löseverhalten zeigt sich der positive Einfluss des Fasenwinkels φ auf das übertragbare Torsionsmoment. So können formend gefügte Stahl-Aluminium- Rändelpressverbindungen ein um bis zu ca. 40% größeres statisches Torsionsmoment als vergleichbare schneidend gefügte Rändelpressverbindungen übertragen. Das mechanisch-physikalische Berechnungsmodell zur Berechnung des statisch übertragbarenTorsionsmomentes basiert auf der Kerbzahnverbindung. Damit kann das Torsionsmoment am Auslegungskriterium T pF sowie das maximal übertragbare Torsionsmoment bei Abscherung Tτ S ermittelt werden. Die Berücksichtigung des formenden beziehungsweise schneidenden Fügevorgangs wird in Abhängigkeit des Fasenwinkels φ mit Hilfe des sogenannten winkelbasierten Umformgrades ε plRPV beschrieben
The present thesis provides analytical, numerical and experimental fundamental studies for the joining behaviour and the transmission behaviour of a friction and form closure steel-aluminum knurled interference fit. The special feature of this connection is a knurled and oversize hard steel shaft, longitudinally pressed in a soft aluminum hub with a circular bore. The most important parameter for the joining process is the shaft chamfer angle φ. Due to the shaft chamfer angle φ the material of the hub will be formed or cutted during the joining process. By using the relative strength, the quotient of push out force and joining force who describes the joint strength, a first quality parameter for a precise selection of steel-aluminum knurled interference fit has been derived. The description of the experimentally determined torque - twisting angle – curves has shown areas of design criterion and mechanical breakdown. The maximum transmittable torque is achieved by reaching the shearing stress of the knurls in the hub - mechanical breakdown τ S. Similar to the joining and the push out behaviour, the positive influence of the shaft chamfer angle φ is also shown at the transmittable torque. Furthermore, knurled interference fits joined by forming can transmit higher torques of about 40% than interference fits joined by cutting due to the material hardening. The mechanical-physical model for calculating the static transmittable torque is based on the serration connection. Thus, the torque at the design criterion and the maximum transmittable torque at the mechanical breakdown can be found. The consideration of the forming or cutting joining process is described as a function of the shaft chamfer angle φ using the so-called angle-based plastic strain ε plRPV

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25

Ottman, Michael J., and M. T. Rogers. "Alfalfa Yield Response to Cutting Height and Cutting at Dawn and Dusk." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/204089.

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Alfalfa yield and quality can be affected by the height and timing of cutting. This research was conducted to determine if 1) raising cutting height from 2 to 4 inches could increase stem density particularly during the summer months, and if 2) alfalfa cut at dusk and the following dawn differ in dry matter yield. Alfalfa was harvested from small plots eight times during the year in an experiment conducted at the Maricopa Agricultural Center in 1999 on a third year stand. The 4 inch cutting height resulted in consistently lower yields compared to the 2 inch cutting height even during the summer despite having slightly higher stem density. The 2 inch cutting height produced 12.5 tons/acre over the year compared to 9.9 tons/acre for the 4 inch cutting height. Forage yield was 3.7% higher for alfalfa cut at dusk compared to the following dawn. Alfalfa cut at dusk and weighed the following dawn lost a similar amount of dry weight overnight compared to alfalfa left standing. Any yield advantage of cutting at dusk can only be realized by greenchopping and immediately feeding the forage.

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26

Wikborg, Uno. "Online Meat Cutting Optimisation." Thesis, Norwegian University of Science and Technology, Department of Computer and Information Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8887.

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Nortura, Norways largest producer of meat, faces many challenges in their operation. One of these challenges is to decide which products to make out of each of the slaughtered animals. The meat from the animals can be made into different products, some more valuable than others. However, someone has to buy the products as well. It is therefore important to produce what the customers ask for. This thesis is about a computer system based on online optimisation which helps the meat cutters decide what to make. Two different meat cutting plants have been visited to specify how the system should work. This information has been used to develop a program which can give a recommendation for what to produce from carcasses during cutting. The system has been developed by considering both the attributes of the animals and the orders from the customers. The main focus of the thesis is how to deal with the fact that the attributes are only known for a small number of the animals, since they are measured right after slaughtering. A method has been made to calculate what should be made from the different carcasses, and this method has been realised with both exact and heuristic algorithms.

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27

Wyeth, David James. "The mechanics of cutting." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494413.

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Cutting produces offcuts and chips in many different ways. One such process is where the chip is formed along a plane of shear inclined from the tool tip to the workpiece surface. This shear plane cutting process, found when cutting many different materials, comprises friction, plasticity and material separation. The importance of including material separation in the analysis is the main focus of this research, which involves the study of chip formation by cutting PMMA and Nylon 66 and wood.

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28

Lönnerberg, Mattias. "Cutting Tetrahedra : Affordances and Limitations of Using Virtual Reality Visualization for Tetrahedral Cutting." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211544.

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Анотація:

Finite element method researchers aim to create algorithms for optimally cutting complex 3D shapes into several tetrahedra for computational efficiency in simulations. It is difficult to create a mental representation of the 3D shapes as they increase in complexity. Our hypothesis is that a virtual reality (VR) visualization could help with creating this mental 3D representation. In this thesis, a desktop tool using a 2D monitor and a virtual reality tool were compared in a controlled within-subject user study. The findings show that VR gave a better understanding of the 3D objects. Participants reported VR to be more intuitive and enjoyable than the 2D monitor. However, it did not improve the time it took to complete the study tasks and, although it made the users perceive that they were more accurate, the observational data suggests that more accurate cuts were made using the desktop tool.
Forskare försöker skapa algoritmer för att optimalt skära komplexa 3D former i flera tetraeder för att simplifiera simuleringar. Det är svårt att skapa en mental representation av 3D figurerna när dom blir mer komplexa. En virtual reality visualisering skulle kunna hjälpa till att skapa denna mentala 3D representation. Genom att skapa ett verktyg för en dator med 2D monitor och ett verktyg som använder VR och därefter jämföra dem i en kontrollerad användarstudie med upprepade försök, visade det sig att VR gav en bättre förståelse av 3D objekten. Det var dessutom mer intuitivt och njutbart. Dock minskade det inte tiden som behövdes för att avsluta studiens uppgifter och trots att användarna uppfattade att dom var mer pricksäkra i VR så påvisade den observerade datan att användare gjorde mer träffsäkra skärningar i verktyget utan VR.

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29

Нагорний, Володимир В`ячеславович, Владимир Вячеславович Нагорный, and Volodymyr Viacheslavovych Nahornyi. "Diagnosis of cutting tool by the sound that accompanies the process of cutting." Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/33557.

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Typical defects of a tool is wear and peeling of tool blade. These defects must be detected in proper time to replace the tool immediately. One of the diagnostic signs of these defects is the sound level which accompanies the cutting process. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33557

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30

Pivetta, Carlos Sergio. "Uma contribuição ao estudo do fresamento de aço endurecido com fresa de topo esferico." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265603.

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Анотація:

Orientador: Anselmo Eduardo Diniz
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-05T19:57:39Z (GMT). No. of bitstreams: 1 Pivetta_CarlosSergio_M.pdf: 2572259 bytes, checksum: d75f09a259545ac56a46ecc1d5870ba0 (MD5) Previous issue date: 2005
Resumo: O fresamento de cavidades de moldes e matrizes em material endurecido usando ferramenta de topo esférico tem limitações em termos de profundidades das cavidades, da taxa de remoção de cavaco e da vida da ferramenta. Algumas operações de fresamento em cavidades profundas não podem ser realizadas, devido à necessidade de se ter ferramenta com alto balanço, o que gera vibração e, em conseqüência, danos à rugosidade da peça e à vida da ferramenta. Outro ponto ainda não totalmente compreendido é a influência da rugosidade deixada na peça pela operação anterior, na rugosidade da operação de acabamento, já que, devido às baixas profundidades utilizadas nesta operação, a rugosidade da operação anterior pode influenciar a profundidade real removida. O principal objetivo deste trabalho é verificar a influência da relação comprimento/diâmetro da ferramenta (balanço), da rugosidade da operação anterior e da velocidade de corte na rugosidade da peça e na vida da ferramenta de fresamento em acabamento. Para isto foram realizados ensaios de fresamento em aço endurecido AISI D2 (58 HRC) com ferramenta de ponta esférica de metal duro recoberto, variando-se os citados parâmetros de influência. Dentre as conclusões deste trabalho, pode-se destacar: nem a rugosidade da operação anterior, nem o balanço da ferramenta influenciaram a rugosidade da peça, pelo menos nos níveis utilizados neste trabalho; com balanço da ferramenta pequeno, consegue-se baixos valores de desgaste e, com isso, longa vida da ferramenta, mas quando se utiliza conjuntamente balanço da ferramenta e velocidades de corte altas, a vida da ferramenta é bastante reduzida
Abstract: The milling of molds and dies cavities carried out on hardened steel using ball end mill presents limitations in terms of cavity depth, metal removal rates and tool life. Some milling operations on deep cavities are not possible due to the require of long tool overhang, what generates vibrations and, consequently, resulted in poor surface roughness and short tool life. Other point which is not totally understood up to the present is the influence of the surface roughness obtained in the previous operation on the results of finishing operation because on finishing operations, the actual depth of cut is not much larger than the height of roughness left on the surface by the previous operation. The main objective of this work is to verify the influence of the ratio tool overhang/ tool diameter, the roughness of the previous operation and cutting speed on the tool wear in finishing operations. Besides, it also intends to verify the influence of tool wear on the tool vibration, measured through the real time tool deflection. Milling experiments on AISI D2 hardened steel (58 HRC) were carried out using coated (TiNAl) carbide ball end mills with the input variables already mentioned. The main conclusions of this experiments, for the used conditions, were: the previous surface roughness neither the tool overhang have influence on the resulting surface roughness; when the tool overhang was the lowest one, cutting speed did not influence so much tool wear, but when the highest tool overhang was used, cutting speed presented a strong influence on tool wear
Mestrado
Materiais e Processos de Fabricação
Mestre em Engenharia Mecânica

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31

Schmidt, Stuart. "Applied rock cutting : a study of partial face disc cutting with blunt disc cutters /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18740.pdf.

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32

Misner, Scottie, and Carol Curtis. "Cutting Boards (Plastic versus Wood)." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/146435.

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1p.
Revised
Which is better, wooden or plastic cutting board? Recent research has confirmed the conventional belief that plastic is safer than wood for cutting meat and poultry. This article explains the reason why plastic cutting boards are better, and gives recommendations on how to keep cutting boards safe.

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33

Harper, John. "Alfalfa Yield and Cutting Interactions." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/200496.

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34

Dooley, S. "Biodegradation of machine cutting oil." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598601.

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The aim of this dissertation was to improve the biodegradation performance of a machine cutting oil employed in the processing of uranium at AWE. The machine cutting oil is chemically complex containing mineral oil, surfactants to improve emulsification and a phenolic biocide. Biodegradation was performed by a mixed culture of bacteria isolated from used cutting oil. Continuous, semi-batch and fed-batch systems were examined and stirred tanks and well-mixed biosupport reactors (immobilised cell systems) were compared. A continuous flow system was shown to provide a high rate of productivity with respect to COD removal. The extent of biodegradation would be important for a radioactive application and this ranged from 61-77% for hydraulic residence times of 10-53 hours, however it was noted that the extent of biodegradation was greater in the batch start-up period. The application of a Tween 80 emulsified feed to increase the bioavailability of the oil phase inhibited rather than improved the biodegradation performance. The use of a biosupport reactor improved biodegradation at shorter residence times. Development of these observations led to the operation of semi-batch (SBR) and fed-batch reactor systems (FBR). Following acclimatisation of the culture, the semi-batch systems consistently yielded higher extents of biodegradation in the range of 86-94% removal of COD for a bioprocess cycle of 5 days. The addition of n-hexadecane, as a readily metabolised co-substrate, to two semi-batch experiments did not noticeably increase biodegradation. A fed-batch configuration did not improve on the performance of the semi-batch configuration. GC-MS analysis of the extracted organics produced an unresolved complex mixture (UCM). Oxidation using chromium trioxide (CrO₃) of the UCM suggested that the remaining components were undegraded molecules from the base oil rather than excreted biodegradation intermediates. Phenotypic and genotypic assessment of the bacterial community showed that the overall diversity of the mixed culture was low. The bacterial population shifted throughout the batch period and diversity was further reduced as the cutting oil was degraded. Maximum diversity was observed at the start of the batch period and at steady state for the continuous system.

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35

Aluko, O. B. "Brittle fracture in soil cutting." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383949.

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36

Gram, Greta. "SUN PIECE : actions of cutting." Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17071.

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This works explores how to work with Event scores as a design method. In the search for what is real or what is reality the already existing things are being explored. The work started with investigating suitable ways to work with the moving body in the design process, with the aim to find a method that gave control but also left some parameters to the undecided and ambiguous. Convinced that this will lead to something new some parts of the process were highlighted and re-formulated.
Program: Modedesignutbildningen

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37

Zhang, Tao. "High power disk laser cutting." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609511.

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38

Hendricks, Brian Reginald. "Simulation of plasma arc cutting." Thesis, Peninsula Technikon, 1999. http://hdl.handle.net/20.500.11838/1245.

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Анотація:

Thesis (MTech (Mechanical Engineering))--Peninsula Technikon, 1999
The simulation of Plasma Arc Cutting is presented in this study. The plasma arc cutting process employs a plasma torch with a very narrow bore to produce a transferred arc to the workpiece. A technique for modelling plasma arc cutting has been developed by applying the thermo-metallurgical model to the process and integrating a model of material removal to this model. The model is solved using the finite element method using the FE package SYSWORLD, more specifically SYSWELD. The objective is to determine the minimum energy required to cut a plate of some thickness using this virtual model. The characteristics of the cut need to exhibit the characteristics of a "high quality cut". The model presented can predict the kerf size given certain process variable settings. The numerical results obtained are assessed by conducting experiments. By maintaining Ill1rumum energy input cost savings can be made through energy savings, limiting additional finishing processes and reducing expense of shortening the electrode and nozzle lifetimes. The modelling of the PAC process using virtual design techniques provides a cost-effective solution to the manufacturing industries with respect to process specification development. This plays an important role in South Africa's transition into a competitive global market. It is envisaged that the model will provide an alternative more efficient, non-destructive means of determining the optimum process variable settings for the plasma arc cutting process.

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39

Goulimis, Constantine Nicholas. "The cutting stock problem revisited." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/8159.

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The subject of this thesis is the well-known problem in the theory of mathematical programming, the cutting stock problem. Its applications are numerous, occurring whenever material must be cut from "master" items, but this thesis is primarily concerned with the paper industry, where the cutting and slitting of big sheets of paper into smaller ones is an important and cost-sensitive part of the manufacturing process. Algorithms described in Chapters 2 and 3 solve certain classes of such problems to optimality (in the sense of having the least possible waste) in reasonable time. These classes include the one-dimensional problem, the one-and-a-half dimensional problem and certain two-stage problems. For each of these classes we report on industrial case studies in the paper and board industry. This is, apparently, the first time in the published literature that such optimal solutions for these problems have been routinely generated. This work has resulted in the development of two commercial packages - used on a daily basis in six paper and board mills, the first of which was installed in February 1985. In these sites, savings in the range of 1%-5% in utilisation have been achieved as compared against other programs or human practice. in Chapter 4 a heuristic algorithm is developed for rearranging a previously generated solution to reduce the number of knife settings required. Another heuristic takes existing solutions and reduces the number of patterns present in the solution. We describe a general framework for solving assortment problems and examine its application in the paper industry. Finally, statistical techniques are used to answer such "green-field site" questions as what are good geometric characteristics for a paper machine, and what is the relationship between waste and run length.

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40

Hashemzadeh, Majid. "Investigations into fibre laser cutting." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14057/.

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Fibre laser cutting of mild steel using oxygen and nitrogen is widely used in industries throughout the world. An IPG YLR-2000 Ytterbium fibre machine with a maximum power of 2 kW and a wavelength of 1.06 µm is used throughout this research. The effects of oxygen and nitrogen as assist gases on the feature of laser cutting process are different in terms of kerf width, surface roughness, heat affected zone and striation pattern. The kerf width in oxygen laser cutting is wider than that for nitrogen. The striation pattern on oxygen cut edge is smoother than that for the nitrogen cut edge. When using oxygen, the cut edge is covered by a fragile oxide layer while this feature is not seen on the nitrogen cut edge. After laser cutting with oxygen, the cut edge is dross free whilst nitrogen cut edge is drossy. Laser piercing is used to generate a starting point for laser cutting. The pierced hole is normally larger than the kerf width, which means that it cannot lie on the cutline. An experimental programme investigating the piercing process as a function of laser and assist gas parameters is presented. Oxygen and nitrogen were used as assist gases, with pressures ranging from 0.3 to 12 bar. The sizes, geometries and piercing time of the holes produced have been analysed. The pierced hole size decreases with increasing gas pressure and increasing laser power. Oxygen assist gas produced larger diameter holes than nitrogen. A new technique is presented which produces pierced holes no larger than the kerf with and would allow the pierced hole to lie on the cut line of the finished product – allowing better material usage. This uses an inclined jet of nitrogen when piercing prior to oxygen assisted cutting. Specific point energy (SPE) is a concept that has been successfully used in laser welding where SPE and power density determine penetration depth. This analysis allows welding carried out by different laser systems to be directly compared. This work investigates if the SPE concept can be applied to laser cutting. Laser cutting of various thicknesses of mild steel, two different optical set ups and three different delivery fibres with a range of powers and translation speeds is done to gain results for numerous different parameter combinations. It is found that the SPE concept is applicable to laser cutting and the following effects noted: for given material thickness and any given value of SPE, cost is decreased by using a larger beam diameter; for given cut sheet thickness, cutting efficiency increases with SPE; for given value of SPE, cutting efficiency increases as material thickness decreases.

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41

Johnson, Eric P. "Composite strength statistics from fiber strength statistics." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26420.

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Utilization of composites in critical design applications requires an extensive engineering experience data base which is generally lacking, especially for rapidly developing constituent fibers. As a supplement, an accurate reliability theory can be applied in design. This investigation is a part of a research effort to develop a probabilistic model of composite reliability capable of using data produced in small laboratory test samples to predict the behavior of large structures with respect to their actual dimensions. This work included testing of composite strength which was then used in exploring the methodology of predicting composite reliability from the parent single filament fiber strength statistics. This required testing of a coordinate set of test samples which consisted of a composite and its parent fibers. Previously collected fiber strength statistics from two different production spools were used in conjunction with the current effort. This investigation established that, for a well made composite, the Local Load Sharing Model of reliability prediction exhibited outstanding correlation with experimental data and was sufficiently sensitive to predict deficient composite strength due to a specific fiber spool with an abnormally weak lower tail. In addition, it provided an upper bound on the composite reliability. This investigation is unique in that is used a coordinate set of data with an unambiguous genesis of parent fiber and subsequent composite. The findings of this investigation are also definitive in that six orders of extrapolation of size in reliability prediction has been verified

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42

Xu, Shunli. "Modelling the cutting process and cutting performance in abrasive waterjet machining with controlled nozzle oscillation." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16237/.

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Abrasive waterjet (AWJ) cutting is one of the most recently developed manufacturing technologies. It is superior to many other cutting techniques in processing various materials, particularly in processing difficult-to-cut materials. This technology is being increasingly used in various industries. However, its cutting capability in terms of the depth of jet penetration and kerf quality is the major obstruction limiting its further applications. More work is required to fully understand the cutting process and cutting mechanism, and to optimise cutting performance. This thesis presents a comprehensive study on the controlled nozzle oscillation technique aiming at increasing the cutting performance in AWJ machining. In order to understand the current state and development in AWJ cutting, an extensive literature review is carried out. It has found that the reported studies on controlled nozzle oscillation cutting are primarily about the use of large oscillation angles of 10 degrees or more. Nozzle oscillation in the cutting plane with such large oscillation angles results in theoretical geometrical errors on the component profile in contouring. No published attempt has been found on the study of oscillation cutting under small angles although it is a common application in practice. Particularly, there is no reported research on the integration of nozzle oscillation technique into AWJ multipass cutting, which is expected to significantly enhance the cutting performance. An experimental investigation is first undertaken to study the major cutting performance measures in AWJ single pass cutting of an 87% alumina ceramic with controlled nozzle oscillation at small angles. The trends and characteristics of cutting performance quantities with respect to the process parameters as well as the science behind which nozzle oscillation affects the cutting performance have been analysed. It has been shown that as with oscillation cutting at large angles, oscillation at small angles can have an equally significant impact on the cutting performance. When the optimum cutting parameters are used for both nozzle oscillation and normal cutting, the former can statistically increase the depth of cut by 23% and smooth depth of cut by 30.8%, and reduce kerf surface roughness by 11.7% and kerf taper by 54%. It has also been found that if the cutting parameters are not selected properly, nozzle oscillation can reduce some major cutting performance measures. In order to correctly select the process parameters and to optimise the cutting process, the mathematical models for major cutting performance measures have then been developed. The predictive models for the depth of cut in both normal cutting and oscillation cutting are developed by using a dimensional analysis technique. Mathematical models for other major cutting performance measures are also developed with the aid of empirical approach. These mathematical models are verified both qualitatively and quantitatively based on the experimental data. The assessment reveals that the developed models conform well to the experimental results and can provide an effective means for the optimum selection of process variables in AWJ cutting with nozzle oscillation. A further experimental investigation of AWJ cutting of alumina ceramics is carried out in order to study the application of AWJ oscillation technique in multipass cutting. While high nozzle traverse speed with multipass can achieve overall better cutting performance than low traverse speed with single pass in the same elapsed time, it has been found that the different combination of nozzle traverse speed with the number of passes significantly affects cutting process. Optimum combination of nozzle traverse speed with the number of passes is determined to achieve maximum depth of cut. It has also demonstrated that the multipass cutting with low nozzle traverse speed in the first pass and a comparatively high traverse speed for the following passes is a sensible choice for a small kerf taper requirement. When nozzle oscillation is incorporated into multipass cutting, it can greatly increase the depth of cut and reduce kerf taper. The predictive models for the depth of cut in both multipass normal cutting and multipass oscillation cutting are finally developed. With the help of dimensional analysis, the models of the incremental cutting depth for individual pass are derived based on the developed depth of cut models for single pass cutting. The models of depth of cut for a multipass cutting operation are then established by the sum of the incremental cutting depth from each pass. A numerical analysis has verified the models and demonstrated the adequacy of the models' predictions. The models provide an essential basis for the development of optimization strategies for the effective use of the AWJ cutting technology when the multipass cutting technique is used with controlled nozzle oscillation.

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43

Simpson, Angela. "The lived experience of self-cutting and recovery from self-cutting : a co-grounded theory." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417550.

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44

Tangtatswas, Pitjaya. "ALGORITHM FOR THE CUTTING STOCK PROBLEM WITH MULTIPLE RAWS AND LIMITED NUMBER OF CUTTING KNIVES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1486572677758349.

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45

Lätzer, Michael. "Füge- und Übertragungsverhalten torsionsbelasteter Stahl-Aluminium-Rändelpressverbindungen." Doctoral thesis, Universitätsverlag der Technischen Universität Chemnitz, 2015. https://monarch.qucosa.de/id/qucosa%3A20428.

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Die vorliegende Dissertation beschäftigt sich mit analytischen, numerischen und experimentellen Grundlagenuntersuchungen zum Füge- und zum Übertragungsverhalten einer reibformschlüssigen Stahl-Aluminium-Rändelpressverbindung. Die Besonderheit dieser Verbindung besteht darin, dass eine mit einer Rändelung und Übermaß versehene harte Stahlwelle in eine weiche Aluminiumnabe mit kreisrunder Bohrung längseingepresst wird. Die maßgebende Größe für den Fügevorgang ist der Fasenwinkel der Welle φ. Der Nabenwerkstoff wird hierbei in Abhängigkeit des Fasenwinkels der Welle φ umgeformt beziehungsweise herausgeschnitten. Mit Hilfe der relativen Festigkeit R F , welche das Verhältnis von maximaler Lösekraft F l, max zu maximaler Fügekraft F f, max repräsentiert, wurde ein Gütekennwert zur gezielten Auswahl von Stahl-Aluminium-Rändelpressverbindungen hinsichtlich der axialen Übertragungsfähigkeit abgeleitet. Die Charakterisierung der experimentell ermittelten Torsionsmoment - Verdrehwinkel - Kurven ergab zur Auslegung die Bereiche Auslegungs- und Versagenskriterium. Das maximal übertragbare Torsionsmoment wird beim sogenannten Versagenskriterium τ S durch das Abscheren der Rändel in der Nabe erreicht. In Analogie zum Füge- und zum Löseverhalten zeigt sich der positive Einfluss des Fasenwinkels φ auf das übertragbare Torsionsmoment. So können formend gefügte Stahl-Aluminium- Rändelpressverbindungen ein um bis zu ca. 40% größeres statisches Torsionsmoment als vergleichbare schneidend gefügte Rändelpressverbindungen übertragen. Das mechanisch-physikalische Berechnungsmodell zur Berechnung des statisch übertragbarenTorsionsmomentes basiert auf der Kerbzahnverbindung. Damit kann das Torsionsmoment am Auslegungskriterium T pF sowie das maximal übertragbare Torsionsmoment bei Abscherung Tτ S ermittelt werden. Die Berücksichtigung des formenden beziehungsweise schneidenden Fügevorgangs wird in Abhängigkeit des Fasenwinkels φ mit Hilfe des sogenannten winkelbasierten Umformgrades ε plRPV beschrieben.
The present thesis provides analytical, numerical and experimental fundamental studies for the joining behaviour and the transmission behaviour of a friction and form closure steel-aluminum knurled interference fit. The special feature of this connection is a knurled and oversize hard steel shaft, longitudinally pressed in a soft aluminum hub with a circular bore. The most important parameter for the joining process is the shaft chamfer angle φ. Due to the shaft chamfer angle φ the material of the hub will be formed or cutted during the joining process. By using the relative strength, the quotient of push out force and joining force who describes the joint strength, a first quality parameter for a precise selection of steel-aluminum knurled interference fit has been derived. The description of the experimentally determined torque - twisting angle – curves has shown areas of design criterion and mechanical breakdown. The maximum transmittable torque is achieved by reaching the shearing stress of the knurls in the hub - mechanical breakdown τ S. Similar to the joining and the push out behaviour, the positive influence of the shaft chamfer angle φ is also shown at the transmittable torque. Furthermore, knurled interference fits joined by forming can transmit higher torques of about 40% than interference fits joined by cutting due to the material hardening. The mechanical-physical model for calculating the static transmittable torque is based on the serration connection. Thus, the torque at the design criterion and the maximum transmittable torque at the mechanical breakdown can be found. The consideration of the forming or cutting joining process is described as a function of the shaft chamfer angle φ using the so-called angle-based plastic strain ε plRPV.

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46

Gerth, Julia Lundberg. "Tribology at the Cutting Edge : A Study of Material Transfer and Damage Mechanisms in Metal Cutting." Doctoral thesis, Uppsala universitet, Tillämpad materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-183186.

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The vision of this thesis is to improve the metal cutting process, with emphasis on the cutting tool, to enable stable and economical industrial production while using expensive tools such as hobs. The aim is to increase the tribological understanding of the mechanisms operating at a cutting edge and of how these can be controlled using different tool parameters. Such understanding will facilitate the development and implementation of future, tribologically designed, cutting tools. Common wear and failure mechanisms in gear hobbing have been identified and focused studies of the material transferred to the tool, in both metal cutting operations and in simplified tribological tests, have been conducted. Interactions between residual stresses in the tool coating and the shape of the cutting edge have also been studied. It was concluded that tool failure is often initiated via small defects in the coated tool system, and it is necessary to eliminate, or minimize, these defects in order to manufacture more reliable and efficient gear cutting tools. Furthermore, the geometry of a cutting edge should be optimized with the residual stress state in the coating, in mind. The interaction between a compressive stress and the geometry of the cutting edge will affect the stress state at the cutting edge and thus affect the practical toughness and the wear resistance of the coating in that area. An intermittent sliding contact test is presented and shown to be of high relevance for studying the interaction between the tool rake face and the chip in milling. It was also demonstrated that material transfer, that can have large effects on the cutting performance, commences already after very short contact times. The nature of the transfer may differ in different areas on the tool. It may include glassy layers, with accumulations of specific elements from the workpiece, and transfer of steel in more or less oxidized form. Both tool coating material, its surface roughness, and the relative speed between the tool surface and the chip, may influence the extent to which the different transfer will occur.

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47

Dai, Yu-Siang, and 戴于翔. "Strength of Silicon Wafer under Different Laser Cutting Conditions." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/nuv986.

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碩士
義守大學
機械與自動化工程學系
107
There are many cutting methods depending on the material characteristics. The reason for semi-conductor industry is that there are many advantages in the cutting process. Under the condition of non-contact processing,the energy of the laser beam and its moving speed Laser parameters can be adjusted according to material properties, and can be processed for a variety of metals and non-metals, especially for materials with high hardness, high brittleness, and high melting point, and no tool wear and increase cost during laser processing. Laser processing of its non-cutting force on the workpiece can increase the yield and stability. This study will explore the effect of ultrafast laser cutting on the strength of the wafer under different parameter settings, by observing the surface roughness of the sidewall and the different bending strength test schemes such as: Cantilever Beam The results of the Bending Test and the Three-Point Bending Test are presumed to be the cause of the test, and the improvement plan of the test machine is proposed under the existing experimental specifications.

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48

CHUANG, CHIA-LUNG, and 莊佳龍. "Characterization of The effect of Pre-cutting to The Strength of Concrete by Using Cylindrical Specimen." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7y2rbr.

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Анотація:

碩士
國立雲林科技大學
營建工程系
106
Pre-cutting is important for preventing random crack of concrete especially for slab. However, the strength of the concrete around the cutting reduces due to the damage caused by the cutting. The weakened edges of the cutting break easily in its early service life. Strengthening the edges is the only way to prevent the early breakage. To prevent using a real size concrete specimen, cylindrical concrete specimen is used in this study. Pre-cutting is applied, and the strength of the cut specimen is characterized. The decrease of the strength can be characterized by compared with that of the undamaged one. It is found that curing of the cut specimen may recover part of the strength.

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49

Huang, Sheng-Fong, and 黃聖峰. "Analysis on structure strength and rigidity for CNC lathe of a simultaneous turning with multiple cutting-tool." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/77wxa8.

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Анотація:

碩士
國立虎尾科技大學
機械與電腦輔助工程系碩士班
104
Because domestic and foreign machinery manufacturing industry is facing fierce competition, development of complex, simultaneous machining with multiple cutting-tool and intelligent machine tools has become a new trend in the global machine tool development in recent years. Simultaneous processing technique could be overlapped such that machining time of parts may be reduced and the production efficiency can be enhanced consequently. However, due to design space limitation and cost consideration, the turret is usually replaced by a multiple cutting-tool post for a small and simultaneous turning machine. Therefore, it is hard to cover the structure rigidity and fluent movement of feeding mechanism in this multiple cutting-tool post structure in order to satisfy the requirement of dynamic rigidity under the maximum elongation of a simultaneous turning with multiple cutting-tool. In this paper, the machining quality of a simultaneous turning can be enhanced through the improvement both of the structure static and dynamic rigidities. First, for analysis reality, a turning experiment was carried out and the cutting forces were obtained as a boundary condition for stress and strain FEM analysis model. Next, the numerical and experimental modal analyses are performed for a CNC lathe of a simultaneous turning with multiple cutting-tool, and the natural frequency, damping ratio and mode shape of the structure are investigated consequently. At last, according to the above analyses in static and dynamic rigidities, the width of tool shank is widened to enhance the structure static rigidity based on a cantilever beam-deflection theory. Moreover, with reference to a column structure in the C-type machine-tool, increasing the supporting area at lower-half portion of the spindle, lowering the weight of structure and adding some reinforcement ribs at the same time to improve the dynamic rigidity. With the modification of tool shank width in consideration of cost factor, the FEM analysis results show that the maximum total displacement, maximum equivalent stress and strain are decreased about 26%, 38%, and 35%, respectively, in contrast to the dynamic rigidity is not improved significantly. In the final design improvement version, both the static and dynamic rigidities may be improved effectively, the maximum total displacement, maximum effective stress and strain are decreased about 30%, 38% and 35%, respectively. Under the maximum rotational speed of 5000rpm (83Hz) in this CNC lathe, the corresponding natural frequencies of the first-mode to third-mode were increased about 11%, 14% and 2%, respectively.

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50

Lin, Tai-Huang, and 林泰宏. "The improvement on the bonding strength between diamond particles and the piano wire for high speed ingot cutting." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/evddnw.

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Анотація:

碩士
國立交通大學
工學院半導體材料與製程設備學程
101
This thesis is mainly researching for solar cell and light-emitting diode, it can divide ingot into wafer. In this manufacturing process, what it uses is the fixed-abrasive with high speed wire saw. According to the statistics, currently for those sapphire-processing factories in our country, the demand in every month of wire saw is more than 5,000Km, meanwhile adding the demand from solar cell industry, and its finical scale is definitely over ten million. Because of this reason, diamond will be generally used. However, the global market now has been monopolized by Japan Company and the price is always staying high. Therefore, in order to avoid the source monopolized by foreign countries, I worked on this research. This thesis mainly investigates the combination power between diamond and piano wire. In the process of experiment, through the researching and selection, we found that diamond by means of changing its essence of its surface can let our experiment reach the best conditions and that its surface with nickel can make it more magnetic. On the other hand, we can use the magnetic system to make piano wire magnetic and due to the magnet attracting principle diamond will naturally attach on the piano wire. Moreover, as the surface of diamond has coated nickel so when we do the coating procedure, we can coat both diamond and piano wire with nickel, coving the diamond with nickel. What it produced after the experiment is the cutting line and it can do the abrasive test for some stiff and crisp material. As a result, this test is also evidenced that the diamond through the changing of its essence on the surface is appreciate to produce high speed wire saw.

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Дисертації з теми "Strength of the cutting"

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