Дисертації з теми "Bolt-on"
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Lindholm, Marcus. "Column bolt calculation : Column bolt calculation on a 1200T HAP Raufoss aluminium extrusion machine." Thesis, Karlstads universitet, Avdelningen för maskin- och materialteknik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-11516.
Повний текст джерелаRamskill, Thomas Edward. "Effect of Cracking on Lag Bolt Performance." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28643.
Повний текст джерелаPh. D.
Do, Tan Dan. "The effect of bolt spacing on the tightness behavior of bolted flange joints." Mémoire, École de technologie supérieure, 2012. http://espace.etsmtl.ca/964/1/DO_Tan_Dan.pdf.
Повний текст джерелаDavoodi, Mohammad Reza. "Effects of bolt tightness on the behaviour of mero-type double layer grids." Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/646/.
Повний текст джерелаde, Abreu Almeida Fernando. "The effect of bolt clearance and tolerances on the shear resistance of bolted connections subjected to uni-axial loading : A parametric study." Thesis, KTH, Bro- och stålbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240265.
Повний текст джерелаFinch, Aureliano Paolo. "An investigation of methods for identifying and selecting bolt-on dimensions : the EQ-5D-5L case study." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19113/.
Повний текст джерелаAlbright, Dustin Graham. "The Effects of Bolt Spacing on the Performance of Single-Shear Timber Connections Under Reverse-Cyclic Loading." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/34324.
Повний текст джерелаMaster of Science
Burns, Colby Gail. "Influence of Locking Bolt Location on the Mechanical Properties of an Interlocking Nail in the Canine Femur." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1274723870.
Повний текст джерелаQuan, Yuyun 1973. "Finite element analysis of tumbling mill design and operating effects on liner bolt stresses, liner stresses and mill resonance." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99012.
Повний текст джерелаEdström, Jacob, and Pontus Mjöberg. "The Optimal Hardware Architecture for High Precision 3D Localization on the Edge. : A Study of Robot Guidance for Automated Bolt Tightening." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263104.
Повний текст джерелаIndustrin rör sig mot en högre grad av automatisering och uppkoppling, där tidigare manuella operationer anpassas för sammankopplade industriella robotar. Denna masteruppsats fokuserar specifikt på automatiseringen av åtdragningsapplikationer med förmonterade bultar och kollaborativa robotar. Användningen av 3D-datorseende undersöks för direkt lokalisering av bultar, för att möjliggöra flexibla monteringslösningar. En lokaliseringsalgoritm baserad på 3Ddata utvecklas med intentionen att skapa en lätt mjukvara för att köras på Edge-enheter. En restriktiv användning av djupinlärningsklassificering är därmed inkluderad, för att möjliggöra produktflexibilitet tillsammans med en minimering av den behövda beräkningskraften. Avvägningarna mellan edge- och moln- eller klusterberäkning för den valda applikationen undersöks för att identifiera smarta avlastningsmöjligheter till moln- eller klusterresurser. För att minska operationell fördröjning utvärderas även bildpartitionering, för att snabbare kunna starta operationen med en första koordinat och möjliggöra beräkningar parallellt med robotrörelser. Fyra olika hårdvaruarkitekturer testas, bestående av två olika enkortsdatorer, ett kluster av enkortsdatorer och en marknadsledande dator som en efterliknad lokal molnlösning. Alla system utom klustret visar sig prestera utan operationell fördröjning för applikationen. Den optimala hårdvaruarkitekturen visar sig därmed vara en konsumentklassad enkortsdator, optimerad på energieffektivitet, kostnad och storlek. Om endast variansen i kommunikationstid kan minskas visar klustret potential för att kunna reducera den totala beräkningstiden utan att skapa operationell fördröjning. Smart avlastning till djupinlärningsoptimerade molnresurser eller kluster av sammankopplade robotstationer visar sig möjliggöra ökad komplexitet och tillförlitlighet av algoritmen. Enkortsdatorn visar sig även kunna växla mellan en edge- och en klusterkonfiguration, för att antingen optimera för tiden att starta operationen eller för den totala beräkningstiden. Detta medför en hög flexibilitet i industriella sammanhang, där produktändringar kan hanteras utan behovet av hårdvaruförändringar för visuella beräkningar, vilket ytterligare möjliggör dess integrering i fabriksenheter.
Huang, Jinlong, and Hui Wang. "Internationalization through Acquisition : A Case Study of Getinge AB." Thesis, Halmstad University, School of Business and Engineering (SET), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-4834.
Повний текст джерелаBusiness has seen tremendous growth through internationalization over the last several decades. As one of the strategies for companies to internationalize, acquisition has since then been a well-studied subject. Various steps have to be gone through in order to acquire a company. Afterwards, companies need to take different measures to ensure the success of the acquisition. Culture is usually considered as the most important aspect which determines post-acquisition success. The purpose of this master dissertation is to thus investigate company’s internationalization via acquisition regarding the pre-acquisition decision-making and post-acquisition cultural management. The theoretical framework consists of literature of pre-acquisition decision-making process and post-acquisition culture management. These theories are put together in an analytical model where possible connections are intended to achieve. It will also be used as a foundation in gathering and analyzing the empirical data. In a qualitative approach, the empirical data was gathered through semi-structured interview with the president of Getinge International Group. These findings were also complemented with secondary data such as corporate websites, documents and various scientific articles. The findings of the study show that planning, evaluating, negotiating, making the deal and integration are the five essential steps concerning the process of internationalization through acquisition. The authors find out that identifying of acquisition candidates is not necessarily a part of pre-acquisition as the theory may suggest. The distinction between bolt-on and platform acquisition is of critical importance to determine the different criteria and procedure certain company is going to take. This proves to be much more practical, where theoretical support has not been fully established. Both national and corporate cultures are of crucial importance for the success of company’s post-acquisition culture management. According to the finding of this research, two factors seem to link pre and post acquisition process; one is the planning of how future organization is managed; the other is the appropriate choice of managing director.
Martin, Miriam Sharon. "Survey of Management and Marketing Practices on U.S. Cow-calf Operations and Evaluation of Different Captive Bolt Lengths in a Commercial Slaughter Plant." Thesis, Colorado State University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10784935.
Повний текст джерелаFinding ways to objectively measure welfare within different sectors of the beef industry is necessary to continually improve cattle welfare from birth to slaughter. The first objective of Study 1 was to benchmark cow-calf producer perspectives on management strategies and challenges that ultimately affect cattle welfare on ranches in the United States. The second objective of Study 1 was to quantify how producers are marketing their calf crop, their priorities when selecting replacements, and if producers saw value in handling and care guidelines. A total of 1,414 responses from cow-calf producers in 44 states were collected through a survey done in partnership with BEEF Magazine. Thirty questions were asked of producers to gather demographic information, producers’ current handling and health management practices, and how they prioritized industry challenges. As well as establish at what age and through what avenue producers are marketing their calf crop, and gauge producer perspectives on a quality assessment outlining handling and care guidelines.
After analyses of producer responses, it was concluded that the frequency of management methods and decisions are impacted by age, operation size, location, and BQA certification. A higher percentage of respondents who were BQA certified used electronic eartags, followed by freeze branding. A higher percentage of respondents not BQA certified used basic eartags and hot branding. 74.5% of respondents were preconditioning their calf crop. A higher percentage of respondents were preconditioning their calf crop that were BQA certified, than those who were not BQA certified. The most important beef industry challenge identified was cow-calf health and the biggest challenge to producer’s own operation was identified as land availability/price. The most important animal health issues on producers’ operations were identified as Bovine Respiratory Disease, flies, Pinkeye, and reproductive health. By producer age, calf/neonate health was identified as the biggest challenge for respondents under the age of 30. Respondents age 55-70 responded that Veterinary Feed Directive (VFD)/regulations was more of a challenge than any other age group. Respondents with 50 head or less or more than 1,000 head more frequently retained their calf crop through finishing and respondents with 51 to 200 head and 201 head to 500 head more frequently backgrounded and then sold their calf crop. 13.5% of respondents answered yes, a veterinarian had offered to administer a drug for pain management when castrating or dehorning. Of those 13.5% who responded yes pain management had been offered, 54.55% of respondents chose to use a pain relief method. A higher percentage of producers that precondition also indicated that they use a pain relief method when castrating or dehorning more frequently, though it was still a low percentage. Overall, 46.3% of respondents saw value in handling and care guidelines and 54.9% of respondents saw value in a program including source and age verification, a vaccination plan, and handling and care guidelines. Respondents who were BQA certified, had a beef cow inventory of 501 to 1,000 head, who preconditioned their calves and backgrounded them before selling, and who lived in the West more frequently saw value in a quality assessment outlining handling and care guidelines.
The objective of Study 2 was to examine the effects of captive bolt length and breed type on post-stun leg activity in cattle. A total of 2,850 Holstein (HOL) and non-Holstein British/Continental bred (NHOL) steers and heifers were observed post-stunning at a large commercial slaughter facility. A penetrating pneumatic captive bolt stunner was used with three different bolt lengths: CON, 15.24 cm; MED, 16.51 cm; and LON, 17.78 cm. Hind limb kicking, forelimb activity, take away belt stops, carcass swing and number of knife sticks during exsanguination were recorded for each animal from video recording. Hind limb and forelimb kicks observed ranged from 0 to 25 and 0 to 8, respectively. A significant main effect of treatment, breed type and an interaction between treatment and breed type on hind limb activity was found. Analysis of post-stun hind limb and forelimb activity indicated that increasing pneumatic captive bolt length does not decrease post-stun leg activity but alternatively can increase kicking when using the longest bolt tested in particular types of cattle, i.e. Holsteins. Other parameters associated with the shackling and hoisting process were impacted by breed type as well. There was a higher percentage of cattle experiencing take away belt stops and carcass swing in HOL as compared with NHOL. (Abstract shortened by ProQuest.)
Mothersille, Devon Kenningtham Vernon. "The influence of close proximity blasting on the performance of resin bonded bolts." Thesis, University of Bradford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329297.
Повний текст джерелаCravotta, Stefan, and Emanuele Grimolizzi. "Simulation of vehicle impact into a steel building : A parametric study on the impacted column end-connections." Thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172341.
Повний текст джерелаAcosta, Carlos Felipe. "Dependency of loosening parameters on secondary locking features of threaded inserts." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002279.
Повний текст джерелаXu, Weiwei. "Effect of Bolted Joint Preload on Structural Damping." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4794.
Повний текст джерелаKara, Emre. "A Numerical Study On Block Shear Failure Of Steel Tension Members." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606359/index.pdf.
Повний текст джерелаJames, Aricatt John, and Devarajan Velmurugan. "Determination of stresses and forces acting on a Granulator knife by using FE simulation." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH. Forskningsmiljö Produktutveckling - Simulering och optimering, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-28297.
Повний текст джерелаChen, Yi-Song, and 陳義松. "Study on Hexagonal Flange Bolt by Net Shape Forming." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/91722645931067248411.
Повний текст джерела高苑科技大學
機械與自動化工程研究所
100
Hexagonal flange bolt is the second popular bolt in usage compared to hexagonal bolt. It has been generally used in the parts assembly for automotive and motorcycle industries. The advantages are as below: the bearing surface area gets bigger after locking, the clamping force gets distributed, and the stability of the clamping part is higher. The study is mainly to improve the traditional cold multi-stage forming of hexagonal flange bolt, with a view to reaching the goal of near-net-shape forming the forming method of each pass to produce hexagonal flange bolt without flash is replanned. Tool life can be extended, the production costs can be saved, and the product competition can be enlarged. The “SolidWorks” and “Deform 3D” software under condition of the constant shear friction are used to design and simulate the optimal forming process, the forging force loading of each pass, the effective stress, effective strain, the velocity field, and appearance dimensions for each pass can be analyzed, besides an actual experiment is performed to compare with the appearance dimensions of FEM to verify the feasibility of simulation for FEM analysis. The simulation and experimental results show that the near-net-shape forming for hex flange bolts is feasible. Comparing to the traditional way, the new forming method reduces material loss 7%, no flash is generated, 15% percentage of the forging load is reduced, the die life is improved, the production equipment maintenance cost is decreased, furthermore the product quality is improved and the competitiveness is promoted.
Chang, Chin-Wei, and 張晉維. "Analysis of Improving Stress Concentration on Bolt of Threaded Fastener." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/wda27w.
Повний текст джерела國立臺北科技大學
製造科技研究所
101
In this study, the joint is presented for the screw under axial load. As the load and different boundary conditions, the screw will have non-uniform stress or stress concentration problem of a particular few teeth. Therefore, the screw will have local damage and service life be reduced. According to material deformation and stress theory, the study appropriate modify the gap of screw. Let the place contact with the force in first where stress distribute smaller than another part. On the contrary, let the place that has a little gap to contact with the force in second where stress concentration, by this way, the life of the screw will be added. The stress distribution of the contact part of the thread root was analyzed by ANSYS/Workbench. Finally, the balance indicators of stress have been established as the reference of screw stress distribution.
Yen, Chunyi, and 顏俊毅. "The Analysis of Dynamic Simulation on T-91 Rifle Bolt." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/69974303778832955023.
Повний текст джерела國防大學理工學院
兵器系統工程碩士班
100
ABSTRACT The purpose of this study is to create a simple approach to obtain optimum design for T91 rifle using Solid Works CAD and ADAMS software. First, the problems are identified by reviewing literature. Next, T91 rifle model is built in Solid Works CAD software according to actual size. Third, the created model is transferred into a new model for ADAMS software. The parameters of components of T91 rifle and Heydenreich experience function are also embedded in ADAMS software. Finally, by means of simulating, some critical parameters for designing T91 rifle are obtained. These parameters are verified to be approximate to T91 rifle by compare with the design data of T91 rifle. Therefore, the approach created here is verified to be available. In addition, the approach created here is also demonstrated to be able to save duration and cost of R&D and reduce the risks of tests with live ammunition. Keywords: ADAMS mechanism dynamic simulate and analyze, postprocessing, automatic weapon, interior ballistic, SolidWorks computer aided design
Hsu, Chun-Hsiang, and 許鈞翔. "Effect of tempering on torque of 10B33 torque control bolt." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90560126705931487503.
Повний текст джерела國立高雄大學
化學工程及材料工程學系碩士班
101
Torque control bolt is the most common and important fastener in structural steel industry. Torque is often considered as a standard to determine whether the fastener is locked or not. Therefore, a stable torque can ensure that if the fastener is in its service properly or not. Furthermore, it can increase the safety by preventing fastener from breaking or loosing while the fastener is locked too tight or too loose. This study selected the 10B33 torque control bolt as the experimental material. After quenching and tempering, the torque value was measured and broken surface was analyzed by the torque testing machine. The Rockwell hardness tester was adopted to test the hardness of each specimen with different tempering conditions. According to the combination of results, including torque, hardness and the microstructure, the effect of tempering on the properties of 10B33 torque control bolt could be totally clarified. The experimental results showed that the higher tempering temperature is the lower torque value. The soaking time of tempering exhibited a similar result as tempering temperature. The longer time caused a lower torque value. There was also found that when the tempering temperature was fixed the longer soaking time could stabilize the torque value. In other words, the deviation of torque value was getting smaller and smaller. Besides, torque, hardness and tensile strength were proportional to each other. Nevertheless, the torque was inversely proportional to ductility and toughness. On the basis of the microstructure, when the ferrite content increased significantly then the microstructure became more homogeneous either with the higher tempering temperature(467℃, 487℃, 507℃) or the higher soaking time(85minutes, 95 minutes, 105 minutes). This phenomenon had a positive influence on the mechanical properties.
Pei, Gong-De, and 裴功德. "Study on Multi-Stage Forging of Hexagonal Flange Vehicle Bolt." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/22658487834879005372.
Повний текст джерела國立高雄第一科技大學
機械與自動化工程研究所
101
Abstract The study aims at hexagonal flange vehicle bolt to carry out the design development of mold and dies. The four-stage forming has been considered, and two forming methods have: (1) open die forging (case 1), at the last flange trimming, the flash is occurred; (2) closed die forming (case 2 and case 3), the net shape forming is taken into account, no flash is occurred with direct flange forming. The forming characteristics for both methods have been evaluated, considering three cases the net shape forming (case 3) is finally chosen to do the design of mold and dies. In this study, the multi-stage forging analysis of hexagonal flange vehicle bolt can be simulated by three-dimensional rigid-plastic finite element method. Using the SolidWorks drawing software to conduct the dies and the work-piece, the DEFORM 3D finite element software can be used to simulate and analyze assuming constant shear friction; the effective stress, the effective strain, the velocity field, the forging force and the shape dimensions of fastener can be obtained. Moreover, the stress of dies and forging stream line can be analyzed using DEFORM 3D. From the analysis results to realize the bearing stress of dies fasteners for each stage, the failure of mold and dies. Finally, the dimensions of products have been compared to verify the applicability of the FEM simulation analysis. The research results show the flash loss in case 3 of closed die forging is reduced, the forging force 6,057kN is lower than 6,107kN in case 1 of open die forging. The improvement of die stress in case 3 is better than case 2, The maximum error of dimensions is 2.43 % for case I, 1.91% for case 2, 1.23% for case 3. Therefore, the mold and dies of net shape forming in case 3 can reach the forming requirement of hexagonal flange vehicle bolt. Keywords: Hexagonal flange vehicle bolt, Net shape forming , Die stress, Forging force.
Chang, Chen-Chung, and 趙榮吉. "Study on De-phosphorus of High Strength Bolt Material Properties." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/23117760596299474897.
Повний текст джерела高苑科技大學
機械與自動化工程研究所
103
Originating in 1969, the Taiwan fastener industry has existed for 45 years. A wide variety of fasteners are produced, including those for the automobile industry, household electrical appliances industry, architectural engineering, and even the aviation industry. The effects of the high-tensile bolt dephosphoring process on the entire fastener manufacturing process and its organizational characteristics and mechanical properties are analyzed and discussed in this study. Our experimental results reveal that the bolt dephosphoring process must be completed before heat treatment, which can be confirmed with a dephosphoring reagent or metallographic observation. Once bolt heat treatment is completed, bolts without dephosphoring appear to be coated with δ ferrite (delta ferrite) composed of a phosphate coating and a phosphatizing coating, which are not easily removed. Heat treatment with phosphorus results in grain boundary segregation, causing embrittlement and a reduction in lattice bonding forces and resulting in a high risk of fracturing when bolts are used in high-temperature environments or undergo multiaxial stresses. The results could be used as a reference for manufacturers of high-tensile bolts so as to reduce the risk of delayed fractures in fasteners.
HSU, HSIU-PING, and 徐琇萍. "Experimental Study on an All Direction Damper with Bolt Connections." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/67rc5v.
Повний текст джерела逢甲大學
土木工程學系
107
Because the traditional seismic design code cannot bear the damage brought by devastating earthquakes, in addition to keeping the houses from being destroyed by earthquakes, what an earthquake protection technology shall focus on and pursue is the safety of the articles in buildings. Hence, the development and progress of the earthquake protection technology is even more important. The earthquake protection of the structures mainly takes the passive control technology, which can be divided into two major categories of seismic isolation and energy dissipation. Building upon the works of the predecessors, we continued researching and reforming, and have made an innovative development of the earthquake protection technology that is different from those in the past, enabling this technology to be applied to structures more commonly. Because the material used by most dampers is the structural steel of integrally forming, the research utilized the method of screw bolt to connect the aluminum alloy substrate with the energy dissipation bar. Via the test results, we learned that the damper’s energy absorption effect would be affected by the tolerance between the bolted joints if we used the all direction damper connected by the screw bolts. Our suggestion is not to use the bolted joint as the connection method of the damper substrate and the energy dissipation bar. If you really need to use the method of screw bolt to connect them, you can use the material of same properties as the energy dissipation bar to do the welding.
Lin, Kuan-Cheng, and 林冠呈. "The study on washer roundness of Hexagon bolt with washer." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/39ts24.
Повний текст джерела國立高雄應用科技大學
模具系碩士在職專班
104
In this research, it focuses on the washer roundness of Hexagon washer bolt. The company of product is our main product. Because of material cost, the material diameter were divided into 8.5 9.5and 10.5mm in three parts. For identifying the difference on washer roundness, we use 10.5mm to analyze product by DEFORM and improve the problem . The study for the effects of difference diameters. Adopting the extrusion method to find the relation between Percentage of area reduction and load are in direct proportion on first stage. The heading stress at second stage, which is concentrated on the head. The load will reduce by 1.4%~11.9% through the change of head thickness. The pre-forming at third stage, which is important process to directly impact the appearance of product. In this study, the key to shortage of washer roundness in the pre-forming. The height of pre-forming Hexagon must be higher than final product at 55%. finally, we find out the washer of product is close to circle.
Su, Chia-Yi, and 蘇家毅. "Study on Dynamic Temperature Rising Characteristics of High Speed Rotating Bolt." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5u4n26.
Повний текст джерела國立勤益科技大學
機械工程系
106
Precision locked nut is an indispensable part of the ball screw and the precision high rotating spindle. If the ball screw or the precision high rotating spindle bearing is not subject to axial force preloading, the ball in the bearing will slide so that the bearing inner ring track and the outer ring track will cause greater friction. However, the high temperature will generate under long-time rotation or high-speed rotation; the temperature rise will affect the overall precision and life of the machine tools or special machine. When the precision locked nut was locked on the bearing by a proper axial force preload, the balls in the bearing will roll between the inner ring track and the outer ring track of the bearing so that is reduce the sliding friction and causing a lesser temperature rise. Machine tools or special machines will cause vibration during heavy cutting and the bearing temperature to rising, after a long period of vibration, the tightening force of the precision lock nut may be reduced, which indirectly affects the bearing's pre-axial force. The temperature rise will reduce the axial force of the ball screw or the precision high rotating spindle. An experiment is simulate by simulating a real dynamic testing machine, and the characteristic equation of temperature rise prediction was established. In addition, Taguchi method design experiments are conduct to investigate the installation of precision lock nut under different conditions, to reduce the effect of temperature rising on the reduction of axial force. In this study, the quality characteristics are axial ratio of temperature rise, temperature after bearing testing, axial displacement, ratio of axial force and ratio of anti-loosening torque. The control factors are the fit clearance of the thread, the viscosity of the lubricant, and the bearing contact angle. The best quality characteristics were obtain through the Taguchi method.
Chen, Yi-Xiang, and 陳宜翔. "The Behavior of Hollo-bolt and It’s Application on Steel Tubes Connections." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/5nbhz9.
Повний текст джерела國立臺灣科技大學
營建工程系
105
In this study, the behavior of single Hollo-bolt and steel column joint is discussed. This thesis also includes bolt material test, sleeve material test, Hollo-bolt pre-tension test, Hollo-bolt direct tensile test, Hollo-bolt direct shear test, Hollo-bolt holes bearing test and steel tube connection joint test. The experimental results show that: (1) The applied tightening torque of Grade 8.8 Hollo-bolt is the same as that of Grade 8.8 high-strength bolt. The pre-tensioning force of Grade 8.8 Hollo-bolt can only reach 29% to 75% of the specified value in the provision. The applied tightening torque of Grade 10.9 Hollo-bolt is lower than that of Grade 10.9 high-strength bolt. The pre-tensioning force of Grade 10.9 Hollo-bolt can only reach 18% to 38% of the specified value in the provision. In addition, the direct tensile test and direct shear test show that the Hollo-bolt slips earlier than high-strength bolts. This result indicates that the pre-tensioning force of Hollo-bolt is lower than that of high-strength bolts. (2) The pre-tensioning force of Hollo-bolt cannot reach the value which is specified in the provision. For joint design, the use of slip-critical connection is not recommended. (3) The failure mode of Hollo-bolt direct tensile test is sleeve leg fracture. To evaluate the tensile strength of Hollo-bolt, the tensile strength formula of high-strength bolts should not be used. In this study, an equation is proposed to evaluate the tensile strength of Hollo-Bolt. The proposed strength reduction factor is 0.63. (4) To evaluate the shear strength of Hollo-bolt, it is recommended to assume the shear plane cuts through the sleeve and the strength reduction factor of 0.7 is used in the calculation. (5) To evaluate the hole bearing strength of Hollo-bolt, the clear end distance of 1.53 times the sleeve diameter is recommended to be used for the calculation of the bearing strength upper limit. (6) When Hollo-bolt is used together with rubber washer, the thickness of the connection plate should be greater than 8 mm to avoid the bolt head failure mode. (7) When torque is applied to Hollo-bolt, metal washer is not necessary to be tightly fixed with a wrench. To have metal washer tightly fitted with the steel plate, force is applied to the bolt head. In addition, it is noted that rubber washer should not be outside the bolt hole.
Huang, Jyun-Siang, and 黃俊翔. "The Effects of Bolt Tightening Sequences on The Mechanical Behaviors of Gasketed Flange Joint." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/jz9j73.
Повний текст джерела國立雲林科技大學
機械工程系
102
The deformations and stresses on the flange joint during the bolt clamping are related to the sequences of bolt tightening locations. The preload on the bolt is generated by the torque control method. Nonlinear finite element method is used to simulate the effects of bolt tightening sequences on the contact stresses between the gasket and joint as well the deformations of flange joint. The commercial finite element software ANSYS is used to build the 3-D model of flange joint. The threads on both bolts and nuts are generated to consider the contact forces between threads. Various sequences of bolt tightening on the joint are simulated to compare the effects of the tightening sequences on the mechanical behaviors of the joint. Based on the simulated results, the optimal sequence can be chosen.
Hsu, Ta-Yeh, and 徐大曄. "Study on Ductile Fracture of T-Head Bolt in Multi-Stage Cold Heading Processes." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/61565308698051561738.
Повний текст джерела國立高雄應用科技大學
模具工程系
99
In this study, the size of the t-head bolt which used at automobile needs high-value precision. The t-head bolt are produced by multi-stage cold heading processes. Because the compression rate of head is pretty high during forging, in addition to work-hardening effect, the head is prone to surface crack and affect product strength. At current fastener industry, the design of forming die at fasteners is mainly used by trial-and-error experiences. This study utilizes t-head bolt as an example. Based on the theory of metal forming, and used the software Pro/Engineer to construct the geometry of billet, bolt and die. By using the software DEFORM-3D to analyze multi-stage cold heading processes of the t-head bolt, and then adopt Cockcroft and Latham's ductile fracture criterion to evaluate the workability of the t-head bolt after forming. We could predict timing and location of fracture at the t-head bolt, and compare with the actual results is good agreement. Finally, successfully designed the geometry of die which can reduce the damage value of the original process.
Liu, Hsueh-Chih, and 劉學志. "Effects of Bolt Screwing Sequences on the Efficiency of Proton Exchange Membrane Fuel Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/47fbra.
Повний текст джерела國立中山大學
機械與機電工程學系研究所
106
In this study, a 3D finite element PEMFC (Proton Exchange Membrane Fuel Cell) model has been built and performed the structural analysis, the commercial software ANSYS Workbench 15.0 was adopted in order to observe the effect of bolt pre-loading variation on the contact resistance and porosity of GDL (Gas Diffusion Layer) in PEMFC. The obtained values of contact resistance and porosity of GDL were substituted into the electro-chemistry simulation software Fluent 15.0 to investigate bolts locking sequence on the efficiency of PEMFC was discussed. In structural analysis, the 3D PEMFC model with the reactive area of 9cm2 had been established through 3D drawing software SolidWroks. The model includes membrane, catalyst layer, gas diffusion layer, flow channel plate, current collector and body plate which all elements were assembled by 8 pairs of bolt and nut. In order to apply bolt pre-loading on each pair of bolt and nut, the nuts were assumed to be constrained on xy plane and the ANSYS built-in function, bolt pretension, was adopted. Temperature effect do not consider in this study. In addition, in the order of bolt locking, the bolts are locked in eight times, so the boundary conditions of the model are changed; three different bolt locking sequences (diagonal symmetric lock, intermediate symmetric lock, and clockwise lock) were selected as the purposes of case studies. Different displacements and stress distributions on the inside layers of PEMFC model due to boundary condition changed in each sequence of the bolt locking. From the simulation results, the gas diffusion layer is subjected to the intermediate symmetric locking sequence would maximize the contact resistance and the porosity would be minimal; that lead to increase the ohmic loss as well as reduce the efficiency of PEMFC. Conversely, the diagonal symmetrical locking sequence performed the lowest contact resistance and the largest porosity, so the efficiency of PEMFC is better than the other two locking methods; it could increase the efficiency about 5% by compared with the clockwise locking sequence and about 10.8% by compared with the intermediate symmetrical lock sequence.
WANG, CHUNG-YUAN, and 王仲元. "Tolerance Analysis of the Assemblies with Double Bolt-Hole Fits Based on Combined Factor Method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/qm4efc.
Повний текст джерела國立臺灣科技大學
機械工程系
99
This work studies tolerance analysis methods for the derived dimension of assemblies with double bolt-hole fits. The research starts from investigating the corresponding tolerance chains as the components are dimensioned by conventional or geometrical method. Then factor simulation method is used to analyze the tolerance of a derived dimension of the assembly. It is found that the number of iterations and computation time required in simulation can be significantly reduced by applying the combined factor method to the tolerance chains. Since analytical methods for the tolerance analysis of assemblies with double bolt-hole fits is not available, the data obtained from Monte Carlo simulation is used as the reference for comparison.
Shih, Tzu-Hsien, and 石子賢. "Effects of Different Semi-Elliptical Bolt Holes on the Stress Concentration of Tensile Wooden Members." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/38273044366339721678.
Повний текст джерела國立臺灣大學
森林環境暨資源學研究所
98
Generally, the tensile strength of wood is larger than that of compression strength in longitudinal direction. Because wood tissue could be damaged by metal connector or fastener, stress concentration always occurred at wood near the interface between wood and metal. This is the reason why the tensile strength value is almost close to or even lower than compression value in structural design. In previous reviews, pioneers usually solved many problems by finite element analysis (FEA) simulation and assumed that the wood was isotropic. However, the wood is a kind of anisotropic material rather than isotropic. In fact, it is orthotropic. In this study, a software called Solid Works2008 was used to find the results by FEA. The computer simulation is a tool that an assumed force can apply on a new type of bolt connection in order to reduce stress concentration. Douglas fir (Pseudotsuga menziesii) was selected as the wood member. The material of the bolt was common steel. In this computer simulation, steel was set as an isotropic material. In Cartesian coordinate, the x-direction was assumed in longitudinal direction of the wood. The y- and z-direction represented radial and tangential directions of the wood respectively. The total length of the member is 250 mm, and the width and the thickness are 60 and 12 mm. The hole is drilled in the central. The right side of the hole is a semicircle with 9.5 mm radius a, and the left side is a semiellipse with b mm semimajor axis (or with semiminor axis, if b<a). All the initial sizes are constant, but the length of the semi axis of the semiellipse is variable, so that the definition of the axis ratio R is b/a, where a is the radius of the semicircle. R is set starting from 0.75, and each model with an increment of 0.25 for R was built and analyzed. The applied load was a concentrated force of 980.67 N(100 kgf) on the metal bolt towards the left. The right side of the member would be fixed and could not be moved and there was no deformation or displacement at the end surface. The interface between the wood and the metal bolt was set to free. There was neither glue nor adhesive between them, so there was a clearance while the deformation and displacement happened. Friction was neglected, however. Compared with simulation results, it is evident that the distribution of stress is quite different between isotropic and orthotropic member. But stress concentration still exists in both models at same locations. To enhance the utilization of wood material, the good property of tensile strength of wood should be considered. But stress concentration around the hole will reduce this property. Adjusting the ratio of the axes of R can find a way to reduce the stress concentration. One of the concentrated stresses must be increased while another must be decreased whether the ratio increases or decreases. The simulation show that a good result can be obtained when the ratio R is about 1.2 to 1.25. In the experiment, strain gauges and the universal testing machine were used. Signals were measured and converted through the written computer program. Basically, some of the results are similar with computer simulations. While the applied load is constant, the value of strain at the tensile area by the bolt hole decreases with R increasing, and the value of strain at the compression area by the bolt hole increases with R increasing. However, there were some disadvantages for mechanism such as nodes of wood, grain. And the dimension of the models was too small (limited by the testing machine) that the disadvantages appeared obviously. Because of the small dimension, the scale of strain gauges was enlarged, so that a part of the results were not so accuracy.
張廷舜. "An experimental study on thermal contact resistance and interfacial pressure of bolt-joined aluminum foams." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/57877203388306135488.
Повний текст джерела大葉大學
機械工程學系碩士班
92
An experimental investigation of thermal contact resistance of aluminum foams (Al6061) was conducted. The aluminum foam with a diameter of 63.5 mm was sandwiched between two aluminum cylinders and the whole assembly was fasten by bolts. The heat was transferred through the sample by the one-dimensional thermal conduction. Two types of bolt patterns were used in this study: the first type has 3 bolts with the diameter of 5 mm, and the second type has 6 bolts of 5 mm in diameter. Effects of physical properties of Al foams, such as PPI (pores per inch), R.D. (relative density), and sample height on the thermal contact resistance of Al foams were studied. In addition, the influence of bolt pattern was also discussed. The torque applied on each bolt was in the range from 0.1 to 0.5 N-m. The heat flux through the test specimen was about 50~150KW/m2. In this study, the interfacial pressure between Al foams and Al cylinder was measured by the pressure measuring film. Results show that the interface pressure increases with the increase of applied torque. The contact surface area increases with the interfacial pressure. The variation in bolt pattern produced almost no effect on the interfacial contact pressure. Experimental results indicated that the temperature drop across the Al foam decreases and the total thermal conductance increases when the relative density of Al foam increases. The thermal contact resistance decreases with increasing applied torque, due to the increase of interfacial pressure and contact area. However, the increase of number of bolts from 3 to 6 produced nearly no influence on the contact resistance. An increase in the sample height led to the increase of total thermal resistance, but the contact resistance was independent of the sample height. Among all of the properties, the PPI has most pronounced effect on the thermal resistance. Both total and contact resistances increase with an increase in the PPI value of the Al foam.
Tsay, Che-wen, and 蔡哲文. "Tolerance Analysis of the Assemblies with Double Bolt-Hole Fits Based on Factor Simulation Method." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/89157941576862161024.
Повний текст джерела國立臺灣科技大學
機械工程系
98
This work studies the tolerance analysis of the unconstrained assemblies with double bolt-hole fits. The research starts from investigating the variations of dimension chains for the assemblies with double bolt-hole, clearance fit at different contact positions. Then, the components dimensioned by conventional and geometrical methods are discussed separately. This research focuses on the variations of key dimensions of the assembly while the dimensions of the components have different distributions within the allowable limits. It is found that the factor simulation method can effectively estimate the nominal value and tolerance of the resultant dimensions. Since analytical methods are not applicable to the tolerance analysis of assemblies with bolt-hole fits, the data obtained from Monte Carlo simulation is used as the reference for comparison.
Ngo, Thanh –. Nghi, and 吳清毅. "INVESTIGATING THE OPTIMUM COLD FORGING PROCESSES CASE STUDY ON THE CARBON STEEL HEX BOLT M8x25." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/68501367134598943598.
Повний текст джерела國立高雄應用科技大學
精密模具與機械產研碩士外國專班
99
ABSTRACT Cold forging process can be described as the process where a metal is plastically deformed at room temperature with application of huge pressure. The process not only changes the shape but also improves the properties of the forged parts. In cold forging process, forming load is one of the most important factors. It affects mechanical durability as well as fatigue life of die. Forming load is expected as low as possible. This study will investigate the design of cold forging die for hex bolt M8x25. DEFORM 3D software and Taguchi method was used to optimize forming load by changing some design parameters. The simulation was carried out with an orthogonal array (L9) based on the Taguchi method. The results showed that the optimal values of parameters are rake angle in process 2 at level 1 (1o), across flats distance in process 2 at level 1 (12.7 mm), draft angle in process 2 at level 1 (25o) and rake angle in process 3 at level 3 (3o). After optimizing, the optimized parameters reduced the forming load of top die in process 3 by 26.6% (5.13x104N comparison with initial value 6.99x104N).
Peng, Shau-yu, and 彭紹禹. "Pre-load and bolt-hole clearance effects on load distributions in single-lap bolted joint." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/52094031708056217826.
Повний текст джерела逢甲大學
機械工程學所
99
In structural design, a bolt joint is a very critical issue that can never be ignored. This thesis uses a nonlinear finite element method to study the stress distribution of the single-row multi-lap joint under different bolt-hole clearances and pre-loads. Under the condition of no pre-load, comparisons of five bolts structure with non-clearance and five bolts structure with the same clearance showed that the stiffness of the bolt joint decrease and the stress reduces and becomes nearly equal. After increasing the clearance of the first bolt-hole, with applied shear and torsion loading, the second bolt withstands the stress from the first bolt and reduces the load. However this trend does not exist when bending load is applied. In the bolt structure, regardless of the clearance, with pre-load the bolt stiffness increases and both plates bond closely withstanding the load evenly, which results in stress reduction for each bolt. Although the bolt withstand a larger load, when the load is too heavy the bolt joint fails to bond together.
Li, Si-Wei, and 李思維. "Effect of Bolt Arrangement on Slip Behavior of Slip-Critical Connections with Thermal Sprayed Coating." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/b86p6u.
Повний текст джерела國立交通大學
土木工程系所
107
In this study, thermal sprayed coating was applied to the faying surface of steel plates in order to increase the slip coefficient and enhance the slip resistance of the slip-critical joint. Moreover, this study aims to explore the effect of bolt arrangement on slip resistance. Slip tests of slip-critical connection using eight high-strength bolts were carried out to explore the effects of different bolt arrangement on the slip coefficient, bolt pretension, stress on the splice plate, and slip resistance. Splice plates of the specimens were thermal sprayed coated with 150
Chen, Yi-Fan, and 陳逸凡. "Research on Thermal Contact Resistance of Bolt-Jointed Interface and Heat Conduction Characteristics of Aluminum Honeycombs." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/38067589770568987537.
Повний текст джерела大葉大學
機械工程研究所
90
This thesis is divided into two parts: the first part of this thesis is “Research on Thermal Contact Resistance of Bolt-Jointed Interface”, and the second part of this thesis is “Research on Heat Conduction Characteristics of Aluminum Honeycombs”. The first part of this thesis was an experimental study of thermal contact conductance which was conducted with pairs of aluminum alloy specimens (6061-T6) jointed by bolts. Three different bolt patterns and three different bolt-shaft diameters were adopted in this study, and the torque applied on each bolt was between 1 and 10 N-m. A pressure-measuring film was inserted between samples to determine the interfacial contact pressure of bolt-jointed specimens. Results show that the interfacial contact pressure increases with an increase of either the applied torque or the number of bolts. The interfacial temperature difference across the junction was substantially reduced for bolt-jointed specimens, when compared with two superimposed samples without bolts. With the same bolt number, the variation of bolt-shaft diameter from 5 to 8 mm yields nearly no influence on the thermal contact conductance. However, with the same bolt size, the thermal contact conductance of samples jointed by 8 bolts was much larger than that of 4-bolt samples. The increase of contact surface roughness of test specimens leads to a decrease of thermal contact conductance. When an RTV silicon layer was used as the interstitial material, the total joint conductance was increased with a decrease of the thickness of RTV silicon layer. The second part of this thesis was to study experimentally the heat conduction characteristics of aluminum honeycombs. The honeycombs used in this study were made of Al3104-H19 and Al3003-H16. The cell diameters of honeycombs were 6.3 and 12.7 mm. Temperature measurement shows that the temperature drop across the honeycomb sample is lower for the honeycomb with a smaller cell diameter. Results indicate that the axial total thermal conductance is higher for samples with a smaller cell diameter. For honeycombs with different materials, the axial total conductances were very close in the torque range used in this study. The increase of either the number of bolts or the bolt-shaft diameter leads to an increase of the axial total conductance. The axial contact resistance between aluminum honeycomb and aluminum alloy sample about 10﹪of the axial total resistance. In addition the axial contact resistance of honeycombs with a cell diameter of 6.3 mm decreased with the increasing torque. However for the honeycombs with a cell diameter of 12.7 mm, the torque and the bolt pattern produce nearly no influence on the thermal contact resistance. In the same direction of the aluminum honeycomb, the contact resistance is almost independent of the honeycomb height, but the total resistance decreases with the increasing height of samples.
Fang, Chao-Chun, and 方朝俊. "Influence of Fire Temperature on the Behavior of Weld and Bolt Connections of Fire-Resistance Steel Structures." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/19055483476862453447.
Повний текст джерела國立臺灣科技大學
營建工程系
88
Fire —resistant steel (FRS) possesses good mechanical properties at high temperature. Using FRS can reduce the demand of fire proofing material, shorten the construction period, and increase the usable inner space of a building. Since the behavior of connections play an important role on the safety of steel structures, this research studies the properties of weld and bolt connections of FRS members due to fire load. A series of experiments including residual stress, welding property and the pre-stress loss of high-tension bolt were conducted. The test results shows that the maximum residual stresses of a built-up sections could exceed the yield strength of the steel, while it drops down noticeably after fire exposure. The distribution of residual stress depends on the cooling rate of the welded members. The strength and toughness of the welding material do match that of the FRS material, however the impact toughness is a little insufficient after fire exposure. The mechanism of load transmission of bolt connection has two types, i.e., the friction type and the bearing type. This research evaluates the pre-stress loss of high-tension bolt due to fire temperature by investigating the slip behavior of the bolt at high temperature. The result shows that under the action of temperature below 400℃, the pre-stress of FRS bolt increases a little bit as compared with that at room temperature. It decreases rapidly at temperatures over 400℃, and drop down to about 10% of that at room temperature as the temperature goes beyond 600℃.
Wang, Jui-Yun, and 王瑞雲. "The Study of the H-M Curve and Microstructure on The Carbon Steel and Alloy Steel Bolt Wire Materials." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/fjgg26.
Повний текст джерела高苑科技大學
機械與自動化工程研究所
102
The main purpose in this study is to investigate the relations among hardness-(H-M) -parameter curve and microstructure for the rod wire materials which are normally applied in carbon steel and alloy steel of screws, bolts, and so on by using quenching and different tempering temperature and time and also to investigate the change between tempering temperature and structure through analyses by Electron Microscopes and Energy Diffusion Spectrum. The results are shown from the H-M curve that the SCM wire material is the best one for the resistant ability under high temperature tempering but the 10B33 wire material is the worst. Also the tempering hardness can be figured out from the curved diagram under any temperature and any time and all the mechanical properties like the yielding strength, tensile strength, elongation and surface reduction rate with different bolt wire materials can be derived. If the tempering time is prolonged to 24 hours, then the crystal granules on the base structure will grow onto coarse crystal types. This causes tensile strength, yielding point, and hardness to decrease gradually according to the increase of the tempering temperature. On the other hand, SCM435 is added with stable carbon elements like Cromium and Molybdenum, so when the heat treatment is under quenching or tempering, decarbonizing becomes slower. Therefore, the S45C and 10B33M wire materials are easier to be oxidized to stain skin. This appears a so-called heat treatment coarse grain soft point defect.
Balagopal, R. "Experimental and Analytical Studies on Damage Detection and Failure Analysis of Transmission Towers and Tower like Structures." Thesis, 2016. http://hdl.handle.net/2005/2869.
Повний текст джерела