Dissertations / Theses on the topic 'Riveted'
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1
Imam, Boulent. "Fatigue analysis of riveted railway bridges." Thesis, University of Surrey, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431074.
2
Kecelioglu, Galip. "Stress And Fracture Analysis Of Riveted Joints." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610132/index.pdf.
Abstract:
The objective of this study is to model and analyze a three dimensional single riveted lap joint (with and without a crack). By using finite element method, stress and fracture analyses are carried out under both the residual stress field and external tensile loading. Using a two step simulation, riveting process and subsequent tensile loading of the lap joint are simulated to determine the residual and overall stress state. Residual stress state due to riveting is obtained by interference and clamping misfit method. By employing different interference and clamping misfit values, the effects of riveting process parameters on stress state are examined. Two cracks namely the semi elliptical surface crack at faying surfaces of plates and the quarter elliptical corner crack at rivet hole are the most widely observed crack types in riveted joints. Fracture analysis of cracked riveted joints is carried out by introducing these two crack types to the outer plate at a plane perpendicular to the loading. The mixed mode stress intensity factors (SIFs) and energy release rates (G) around the crack front are obtained by using displacement correlation technique (DCT). Effects riveting process parameters (interference and clamping ratios) and geometrical parameters (crack shape and size) on fracture parameters are studied. The stress intensity factor solutions presented herein could be useful for correlating fatigue crack growth rates, fracture toughness computation, and multiple site damage (MSD) analysis in aircraft bodies.
3
Garcia, Abilio Neves. "Multiple site damage of aeronautical riveted joints." Thesis, Cranfield University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427165.
4
Kim, Jueseok. "Linear Finite Element Modeling of Joined Structures with Riveted Connections." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1563273473791073.
5
Han, Li. "Mechanical behaviour of self-piercing riveted aluminium joints." Thesis, University of Hertfordshire, 2003. http://hdl.handle.net/2299/14159.
Abstract:
The introduction of alternative materials and in particular aluminium alloys, for vehicle body applications has impelled the development of new joining techniques. Traditional joining methods such as spot-welding and arc-welding are being challenged. Self-piercing riveting has attracted considerable interest by the automotive industry and has been used as an alternative to spot-welding in vehicle body assembly. However, self-piercing riveting is a relatively new joining method and as such it is not well understood. The aim of this project was therefore to develop an understanding of the mechanical behaviour of self-piercing riveted joints. The effects of paint-baking, shelf-life, pre-straining and surface condition of the sheet material on the joint quality and behaviour were therefore examined. Aluminium alloy sheet materials, 5754 and AA6111, were used in this investigation. The project began with a metallographic inspection of cross-sections of samples that were joined under different conditions in order to examine the effect of process variables on the joint quality. This part of the investigation led to the identification of suitable setting parameters that produced joints which, by metallographic inspection, were of good quality. It was also observed that some process variables, such as sheet thickness combination, rivet and die design and setting force, affected the joint quality and therefore needed to be taken into consideration in the choice of the processing parameters. Subsequent work focused on mechanical testing. Lap shear, T-peel, pull-out and fatigue tests were carried out in order to examine the mechanical behaviour and to analyse the failure mechanisms of the joints. The work showed that the strength, the thickness and the surface condition of the riveted sheets affected the strength and the failure mechanisms of the joints. The joint strength was also observed to be dependent on the rivet and anvil design as well as the setting force. In addition, the joint strength and behaviour differed as the specimen geometry thus emphasising the need for a test standard for self-piercing riveted joints. Paint baking led to a marginal and insignificant reduction in the static strength, whilst resulting in a reduction in the fatigue strength of the joints as a consequence of recovery of the 5754 alloy and the removal of the wax-based surface lubricant. The effect of 3%, 5% and 10% pre-straining of the 5754 sheet on the quality and performance of the self-piercing riveted joints was also examined. It was established that it was possible to produce joints of good quality, higher strength and superior fatigue performance by using the same setting parameters as for joints without additional pre-straining. An investigation of the effect of the shelf-life of AA6111 indicated that this only had a minor and insignificant effect on the joint quality and behaviour. It was therefore deduced that the quality and performance of joints would not be compromised even after an AA6111 self-life of 21 months. The effect of the interfacial characteristics on the joint quality and behaviour was examined by placing a PTFE layer at the interface between the riveted sheets. It was observed that the PTFE insert significantly reduced the joint strength and changed the failure mechanism. Three distinct failure modes, referred to as rivet pull-out, rivet fracture and sheet material failure, were observed during this investigation. All shear tested samples failed by rivet pull-out. The same failure mechanism was the only one observed for the pull-out tests. The failure mechanism for the peel test depended on the thickness of the rivet sheet. For joints with a (1 mm+2mm)/(0.9mm+2mm) combination, fracture of the thinner sheet material dominated the failure mechanism, whilst for joints with a (2mm+2mm) combination, rivet pull-out was the only failure system. Rivet fracture and sheet material failure were also observed during fatigue testing. Examination of samples following fatigue testing led to the observation of fretting which had not been reported by previous investigators working with self-piercing rivets. Fretting had an important effect on the fatigue strength and fatigue failure mechanisms. Inspection of fatigue fractured samples which were tested at maximum applied loads ranging from 50% to 85% of the ultimate shear load of the joints exhibited fretting scars at three different interfaces. Flange-face fretting was observed to take place at one side of the interface between the two riveted sheets and led to the formation of mainly A1203 debris. Pin-bore fretting was observed to occur between the rivet shank and the aluminium alloy sheet and led to debris containing oxides of aluminium and iron together with the oxides of zinc and tin from the wear of the corrosion protective coating of the rivet. Both types of fretting were affected by the applied load and the surface condition of the riveted sheets. Further examination indicated that fretting contributed to the initiation and propagation of fatigue cracks. The failure modes during fatigue testing were affected by the fretting behaviour and were dependent on the applied load and the interfacial conditions. A PTFE layer introduced a very low coefficient of friction leading to a significantly reduction in the amount of fretting. However, this was accompanied with a change in the load transfer mechanism resulting in rivet fracture and a shorter fatigue life. The paint-baking process led to the removal of the wax-based surface lubricant and fretting cracks therefore initiated at an earlier stage of the fatigue test. In addition, fretting also led to a significant work-hardening of the riveted sheets. It was observed that there was an increase in microhardness at the regions immediately below the fretting area from the riveted sheets. The depth of the work-hardened area below the fretting interface after different periods of fretting represented the depth of damage as a result of fretting fatigue. It was therefore further indicated that fretting played an important role in the fatigue behaviour and would probably affect the crash behaviour of the joints. The effect of secondary bending, an inherent feature of lap joints, was examined and analysed using strain gauge measurements. It was established that secondary bending contributed to the failure mechanism and led to a significant reduction in the fatigue strength of such joints. Using the experimental data an analysis has been carried out to predict the fatigue strength in the absence of secondary bending.
6
Abdulla, Warda Ibrahim. "FATIGUE BEHAVIOR AND SCALE EFFECTS IN RIVETED JOINTS." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron161651595564376.
7
Bejgum, Mahesh. "TESTING AND ANALYSIS OF HEAVY DUTY RIVETED GRATINGS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1154492162.
8
Cinnam, Vikas Kumar Cinnam. "GRILLAGE ANALYSIS OF HEAVY-DUTY RIVETED STEEL GRATINGS." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1525796487234452.
9
Krishnappa, Uma Shankar. "Numerical investigation of self-piercing riveted dual layer joint." Thesis, Wichita State University, 2008. http://hdl.handle.net/10057/2105.
Abstract:
Self-piercing riveting (SPR) is a high-speed mechanical fastening technique for point joining of sheet-material components. SPR is becoming important in automotive applications for aluminium vehicle body assembly. However, compared with current sheet-metal joining processes in the automotive industry, the effects of various parameters such as mechanical properties, rivet setting methods and systems, methods of removing self-piercing rivets, etc. A study examining the effect of specimen configuration on the mechanical behavior of self-piercing riveted, dual-layer joints in aluminium alloys was conducted. It has observed that the specimen configuration had a significant effect on the strength and failure mechanism of a self-piercing riveted dual-layer joint. The basic aspects of SPR process forming by conducting both explicit and implicit analysis have been investigated in this thesis. It was found that the operating force-deformation curve of SPR process was determined by the rivet deformation force and its displacement. Under certain process conditions, an increase in inertia effect due to high velocity of metal forming process results was not significant to an extent. In this research, the springback characteristic parameters of the SPR process were also studied. The springback analysis carried out at the end of the forming process showed that the dimensional change in the part due to springback was not significant.Wichita State University, College of Engineering, Dept. of Mechanical Engineering
Includes bibliographic references (leaves 51-53)
10
Krishnappa, Uma Shankar Lankarani Hamid M. "Numerical investigation of self-piercing riveted dual layer joint." A link to full text of this thesis in SOAR, 2008. http://hdl.handle.net/10057/2105.
Abstract:
Wichita State University, College of Engineering, Dept. of Mechanical Engineering.Copyright 2008 by Uma Shankar Krishnappa. All Rights Reserved. Includes bibliographical references (leaves 51-53).
11
Scott, Jason P. "Corrosion and multiple site damage in riveted fuselage lap joints." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq22127.pdf.
12
Scott, Jason P. (Jason Philip) Carleton University Dissertation Engineering Mechanical and Aerospace. "Corrosion and multiple site damage in riveted fuselage lap joints." Ottawa, 1997.
13
Ioannou, John. "Mechanical behaviour and corrosion of interstitial-free steel-aluminium alloy self-piercing riveted joints." Thesis, University of Hertfordshire, 2010. http://hdl.handle.net/2299/4611.
Abstract:
The overall aim of the project is to examine the rivetability of new steels and to investigate the mechanical behaviour of self-piercing riveted (SPR) aluminium-steel hybrid structures for automotive applications. Interstitial Free Steel (I.F.) of 1.2 mm thickness was joined to Aluminium 5754 of 2 mm thickness and Aluminium 5182 (coated and uncoated) of 1.5 mm thickness. The work began by initially conducting a quality assessment of the various joints that were produced in order to establish the optimum conditions for joining the various sample combinations to be investigated. A relationship was established between the head height and the interlock distance on the one hand and between the interlock distance and the lap shear strength of samples. It was also established that for higher lap shear strength, it is preferable to use the stronger material (I.F. steel) as the pierced sheet and the weaker material (5182) as the locked sheet. However, the results showed that this rule could not be applied for predicting the fatigue behaviour of SPR joints between I.F. steel and 5182. An investigation of the fatigue failure mechanisms was undertaken and possible reasons for this behaviour are discussed. The influence of fretting was also investigated by using scanning electron microscopy and reported. The fatigue behaviour of Dual Phase (DP600 + 5182) SPR joints was investigated. It was observed that the position of fatigue crack initiation differed with the maximum applied load. An explanation for this observation was provided by considering the failure mechanism of the samples under different load levels. The study also showed how fretting led to the initiation of fatigue cracks. The corrosion behaviour of (I.F. steel + 5182) samples was investigated by conducting tests in a salt spray according to the ASTM B117-97 standard. Three types of corrosion were observed; galvanic corrosion, differential aeration corrosion, uniform corrosion and are discussed. The weight change with time was monitored and was used to describe the corrosion behaviour. The lap shear strength was measured as a function of corrosion time. The presence of the corrosion product within the overlap was observed to greatly influence the lap shear strength behaviour. A further study was carried out in order to examine the influence of the individual alloys on the corrosion of the SPR samples. In this part the potential influence of pulse current treatment on corrosion was also investigated and was observed to increase greatly the corrosion resistance of the I.F. steel. Principal findings for this observation are also provided.
14
Haj, Khan Mirza Sarraf Majid. "Experimental study on cyclic behaviour of riveted stiffened seat angle connections." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6588.
Abstract:
Riveted Stiffened Seat Angle Connections have been used as beam-to-column joints in many old steel buildings. These connections are generally categorized as flexible. A concern exists as to the lateral resistance of frames built with these connections, particularly under earthquake excitations which can cause these connections to undergo severe inelastic excursions. An experimental program was conducted to investigate the behaviour of two typical Riveted Stiffened Seat Angle Connections and the improvement in their behaviour when retrofitted using two suggested retrofitting techniques. Large inelastic cyclic tests were conducted on connections taken from an 83 years old building and their hysteretic moment-rotation curves were obtained. Preliminary models of their inelastic behaviour are developed. Practical recommendations for seismic rehabilitations are formulated.
15
Chessman, Kevin Curtis. "Seismic response of existing buildings constructed using semi-rigid riveted connections." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9352.
Abstract:
The use of riveted semi-rigid connections was wide spread in building construction in the first half of the 20th century at a time when earthquake design was not required. It is therefore legitimate to question the seismic response of these historic buildings. Recent experimental work has shown that these connections can develop stable hysteretic moment rotation behavior, but must undergo large rotations in order to reach moderate moment capacity. This raises important concerns about the ability of buildings having such connections to withstand earthquakes while undergoing large drifts. An 18-story building located in Eastern Canada has been surveyed and modeled using a non-linear inelastic dynamic analysis program. It was investigated whether this type of building can survive major earthquakes in spite of having low-strength semi-rigid connections such as those described above. Other generic structures of different heights, based on this existing building, have also been considered and modeled. Seismic ground motions typical of Eastern and Western Canada have been used to generalize the results obtained. It was observed that old buildings of the type modeled in this study have much larger masses due to heavier floors and thicker cladding than their modern counterparts. The buildings also have considerably less rigidity, as a result of semi-rigid connections. The ensuing large period favorably impacts their seismic response. However, results demonstrate that small earthquakes cause considerable drifts, which can translate into non-structural damage in spite of the survival of the primary structure.
16
Bajracharya, Bijay Cheraghi Hossein Krishnan Krishna. "Effect of variations of riveting process on the quality of riveted joints." Diss., Click here for available full-text of this thesis, 2006. http://library.wichita.edu/digitallibrary/etd/2006/t085.pdf.
Abstract:
Thesis (M.S.)--Wichita State University, Dept. of Industrial and Manufacturing Engineering." December 2006." Title from PDF title page (viewed on January 29, 2007). Thesis advisers: Hossein Cheraghi, Krishna Krishnan. Includes bibliographic references (leaves 62-64).
17
Sayar, Mehmet Burak. "Determination Of Stress Intensity Factors In Cracked Panels Reinforced With Riveted Stiffeners." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12614060/index.pdf.
Abstract:
This thesis presents a study about the determination of the stress intensity factors in cracked sheets with riveted stiffeners. Stress intensity factors are determined with both analytical method and finite element method for different combination of rivet/stringer spacing and stringer to sheet stiffness ratio. Analytical part of the thesis is a replication of the original study of Poe which assumes rigid rivet connections with no stringer offset. In the analytical part, the whole systems of equations of Poe are re-derived, and it is shown that there are two typographical errors in the expressions for the calculation of the influence coefficients of the cracked sheet and the stringer. Major objective of the analytical part is to develop a computer code which calculates the variation of the normalized stress intensity factor with the crack length for any combination of rivet/stringer spacing and stringer to sheet stiffness ratio. Analytical part of the study also covers the effect of broken stiffener on the stress intensity factor of the cracked sheet. The stress intensity factors of stiffened cracked sheets are calculated by the finite element method by incorporating fastener flexibility and stringer offset. Finite element solutions are performed by Franc2D/L and Abaqus, and comparisons are made. The effect of geometry, fastener flexibility, and stringer offset on the stress intensity factors are studied by presenting normalized stress intensity factor versus crack length curves. Finally, as a case study a sample damage tolerant stiffened panel is designed according to FAR 25 safety criteria. Experiments are performed for determining mechanical and crack growth properties of Al 2124 which is used as the material in the case study. Present study showed that the most significant effect on the stress intensity factor is seen when stringer-cracked sheet offset is included in the analysis model.
18
Cebulski, Laurent. "Caractérisation expérimentale et numérique de la tenue mécanique des assemblages par rivets aveugles : application aux véhicules de transport guidé." Valenciennes, 2002. https://ged.uphf.fr/nuxeo/site/esupversions/e5969303-30e8-4b80-8f52-a3c5d22de55b.
Abstract:
Les constructeurs ferroviaires utilisent de plus en plus le procédé d'assemblage par rivetage qui rend les structures plus modulaires. La rationalisation du nombre et de la répartition géométrique des rivets est primordial pour optimiser le dimensionnement des structures et conserver ainsi l'intérêt de ce procédé d'assemblage. Le premier chapitre aborde l'étude du processus de rivetage avec la réalisation d'essais afin de quantifier l'état de fragilisation induit par ce procédé. Ces essais servent de base à l'élaboration d'un modèle numérique fin destiné à établir une méthode de simulation réaliste de ce type d'assemblages. Le second chapitre présente la réalisation d'essais quasi-statiques de tenue mécanique sur des assemblages rivetés pour deux sollicitations types : la traction-cisaillement et la traction en croix. Le troisième chapitre aborde le thème des assemblages multi-rivets. Une méthodologie de mise en données est proposée et appliquée sur une structure ferroviaireRailway manufacturers use extensively the riveting process with blind rivets that let to make more modular structures. The rationalization of number and geometric distribution of the rivets is a priority to optimize the design of riveted structures in order to preserve the interest of this assembly process. The first chapter concerns the survey of the riveting process, with some riveting tests realised to quantify the fragilisation state induced by this process. These tests are used for the development of a fine numerical model intended to simulate this kind of assemblies. The second chapter deals with some quasi-static tests realized to study the mechanical behavior of riveted assemblies under two typical railway promptings : tension-shearing and cross-tension. The third chapter tackles the theme of multi-rivets assemblies. A methodology to set the data correctly, based on the use of numerical models previously developped, is proposed and applied on a complex industrial structure
19
Arthur, Godwin Addiah. "Fatigue Behavior and Design of Heavy Duty Riveted Steel Gratings in Bridge Decks." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1417461847.
20
Borba, Natascha Zocoller [Verfasser]. "Design and mechanical integrity of friction riveted joints of thermoplastic composite / Natascha Zocoller Borba." Hamburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2020. http://d-nb.info/1219963526/34.
21
Arbex, Alexandra Alvim. "Análise estrutural e de fadiga de juntas rebitadas de uso aeronaútico utilizando o método dos elementos finitos /." Guaratinguetá : [s.n.], 2011. http://hdl.handle.net/11449/97053.
Abstract:
Orientador: Fernando de Azevedo SilvaBanca: José Elias Tomazini
Banca: Silvana Aparecida Barbosa
Resumo: Juntas rebitadas sobrepostas representam elementos críticos na construção de estruturas aeronáuticas quando projetadas à fadiga. Por serem elementos de fixação largamente utilizados na indústria aeronáutica, o estudo de suas propriedades e variáveis à fadiga tem sido cada vez mais amplo. A variável que tem mostrado possuir alta influência na resistência à fadiga de juntas rebitadas é a força de aperto aplicada no processo de rebitagem. A vida da peça tende a ser maior quando o valor dessa força é aumentado. O método dos elementos finitos, que é uma ferramenta de cálculo aplicada nos mais diversos campos de atuação e tem se tornado parte indispensável de projetos mecânicos, é utilizado nesta dissertação para a análise de uma junta rebitada sobreposta de uso aeronáutico. A junta é simulada levando em conta as etapas do processo de fabricação e aplicação, a fim de realizar a análise de seu comportamento mecânico e calcular sua vida em fadiga. Através de um teste experimental de tração monotônica foram obtidos valores de deformação com extensômetros, e é feita a correlação desses dados com o modelo numérico a fim de validar a modelagem. Em seguida são feitas mais duas análises com diferentes forças de aperto, com o objetivo de verificar a influência dessa variação na vida em fadiga da peça.
Abstract: Riveted lap joints represent a critical element in metallic airframe construction when designing against fatigue. These elements are widely used in the aerospace industry, so the study of the fatigue's properties and variables has been increasingly broad. The variable that has shown to have a high influence on the fatigue strength of riveted joints is the clamping force applied to the riveting process. The life of the part tends to be higher when the clamping force applied is increased. The finite element method, which is a calculation tool applied in various fields of activity and has become an indispensable step of mechanical design, is used in this dissertation for the analysis of a riveted lap joint of aeronautic use. The joint is simulated considering the stages of the manufacturing process and application, in order to perform analysis of mechanical behavior and calculate the fatigue life. Through an experimental test of monotonic tensile, strain values were obtained with strain-gauges, and is made the correlation of these data with the numerical model to validate the modeling. Finally two more tests are made with different clamping forces, in order to check the influence of this variation in fatigue life of the joint.
Mestre
22
Leprêtre, Emilie. "Efficacité du renforcement par composites collés vis-à-vis de la propagation de fissures de fatigue pour une application aux structures rivetées." Thesis, Ecole centrale de Nantes, 2017. http://www.theses.fr/2017ECDN0003/document.
Abstract:
La fatigue représente la deuxième cause d’endommagement des structures métalliques anciennes après la corrosion. Celle-ci se manifeste par l’apparition de fissures, dans les zones fortement sollicitées présentant des concentrations de contraintes importantes, et peut mener à terme à la ruine de l’ouvrage. Dans le cas des structures métalliques anciennes, les fissures de fatigue s’amorcent généralement au droit des trous de rivets rendant difficile leur détection par les techniques de contrôle non destructif conventionnelles. De même, les matériaux métalliques anciens de la construction, et notamment le fer puddlé, limitent l’utilisation de certaines techniques. Dans le cadre de ce travail de thèse, l’objectif principal est d’étudier l’efficacité d’un renforcement par composites collés dans le cas de fissures de fatigue émanant de trous de rivets. Pour cela, des éprouvettes de petites dimensions, présentant un perçage central et une unique fissure de fatigue en bord de perçage, ont été considérées. De même, deux matériaux métalliques, acier doux et fer puddlé, ainsi que deux procédés de renforcement PRFC (polymères renforcés de fibres de carbone), à Module Normal et à Ultra Haut Module, sont étudiés. Pour chaque procédé de renforcement, différentes configurations de renforcement ont été testées et notamment la mise en précontrainte du plat composite MN avant collage. Cela a permis de mettre en évidence l’efficacité de la technique de collage de plats PRFC pour un renforcement à la fatigue de matériaux métalliques anciens. Par ailleurs, les expressions analytiques simples proposées pour le facteur d’intensité de contraintes pourront par la suite être utilisés pour une application aux structures rivetées en tenant compte de la présence du rivet ainsi que celle des plaques assembléesAfter corrosion, fatigue phenomenon is the main cause of damage in old metallic structures. Fatigue cracks appear in stress concentration area subject to high stresses, and can lead to the ruin of the bridge. In old metallic structures, fatigue cracks mainly occur at the edge of the rivet hole and are thus difficult to detect with the common non-destructive inspection technique (NDI). Moreover, due to the poor quality of the old metallic materials, particularly puddled iron, some of the NDI techniques cannot be used. The main objective of the present work is to study the effectiveness of carbon fibre reinforced polymer (CFRP) laminates in reinforcing fatigue crack emanating from the rivet hole. Thus, investigations on small-scale specimens were done. These specimens consist of metallic plates with center hole from which one single crack emanates. Two metallic materials, puddled iron and mild steel, and two reinforcement processes were used. These reinforcement processes consist of Normal Modulus (NM) and Ultra High Modulus (HHM) CFRP laminates. Furthermore, symmetrical and un-symmetrical reinforcement configurations are considered as well as pre-stressing NM laminates before application. The experimental results showed firstly the efficiency of the different studied reinforcement configurations in slowing down crack propagation. In conclusion of this work, the achieved results, particularly those in terms of Stress Intensity Factor, could be used for reinforcement of riveted structures by CFRP bonding, taking into account the presence of rivets as well as the presence of the others elements of the assembly
23
Faishal, Kazi Aman Ullah M. Cheraghi S. Hossein. "Impact of riveting sequence, pitch and gap between sheets on quality of riveted lap joints." Diss., A link to full text of this thesis in SOAR, 2006. http://soar.wichita.edu/dspace/handle/10057/645.
Abstract:
Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering."December 2006." Title from PDF title page (viewed on Oct 31, 2007). Thesis adviser: S. Hossein Cheraghi. Includes bibliographic references (leaves 63-64).
24
Bijju, Manikanta. "Failure analysis of self-piercing riveted joint under different loading conditions using finite element method." Thesis, Wichita State University, 2010. http://hdl.handle.net/10057/3666.
Abstract:
In a structure, a joint is considered as the weakest part, and it should not get separated when subjected to loading, so that an unstable collapse of structure can be avoided. It is important to investigate the failure in joint before it is used in a structure. Failure of a joint depends on various factors such as the geometry of joint configuration, sheet strength that are joined, rivet material used, cracks developed during joining, and many other. Self-Piercing riveting process is a new technology for joining sheet metals in automobile and aircraft industries. This process has many advantages over conventional joining processes. In this thesis, the failure of a self-piercing riveted joint is investigated. Failure of three different riveted configurations under 35m/s and 60m/s velocities were predicted using the general purpose non-linear finite element software LS-DYNA.
This research is divided into three stages of work. In the first stage, a 2D simulation of riveting process is carried out over two Aluminum sheets. An r-adaptive methodology is utilized to acquire a higher accuracy of results and to avoid high element distortion. A parametrical study is then conducted to study the effect of rivet penetration velocity and adaptive mesh size varies the quality of the joint. In the second stage of work, a spring back analysis of joint is conducted to study the deformations of work piece after the riveting process. In the third stage, a Peel specimen, a U-shaped single riveted connection, and a U-shaped double riveted connection were investigated for failure under 35 m/s and 60 m/s velocities in both shear and tension testing conditions. Three different loading conditions were used for testing.
The results from this study will show how process parameters can influence the quality of riveted joint, amount of deformations that occur in the work piece after the removal of rigid bodies, and failure load of SPR joint in different configurations.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.
25
Atre, Amarendra. "A Finite Element and Experimental Investigation on the Fatigue of Riveted Lap Joints in Aircraft Applications." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10494.
Abstract:
Aircraft fuselage skin panels are joined together by rivets. The initiation and propagation
of fatigue cracks in aircraft structures at and around the rivet/skin interface is directly related to residual stress field induced during the riveting process and subsequent service loads. Variations in the manufacturing process, such as applied loading and presence of sealant can influence the induced residual stress field. In previous research, the riveting process has been simulated by a 2D axisymmetric force-controlled analysis. The 2D analysis cannot capture the unsymmetrical residual stress state resulting from process variations. Experimental work has also been limited to observing effects of squeeze force on fatigue crack initiation in the riveted lap joint. In this work, a 3D finite element model of the riveting process that incorporates plasticity and contact between the various surfaces is simulated using ABAQUS finite element code to capture the residual stress state at the rivet/skin interface. The finite element model is implemented to observe the effects of interference, sealant and hole quality on the residual stress state using Implicit and Explicit solvers. Effects of subsequent load transfer are also analyzed with the developed model. A set of controlled lap joint fatigue experiments for the different conditions provides validation to the model.
26
Bisson, Marc A. "An experimental study on the cyclic behaviour of riveted stiffened seat angle connection with concrete encasement." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq26301.pdf.
27
Hennuyer, Claire. "Super-élément fini de tôles rivetées pour le calcul des structures." Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0020/document.
Abstract:
La thèse s’inscrit dans un axe de recherche visant à améliorer l’analyse par éléments finis (EF) des structures aéronautiques soumises au crash et à l’impact. L’étude s’intéresse, en particulier, à la modélisation des assemblages rivetés dans les calculs de structures, qui sont des zones de concentrations de contraintes propices à l’initiation de ruptures. Si la rupture de la fixation est maîtrisée, les modes de rupture dus aux perforations sont, quant à eux, difficiles à simuler dans un calcul sur structure complète. Afin de prendre en compte avec précision l’influence des perforations sur la réponse mécanique de telles structures, un super-élément perforé à 8 nœuds a été formulé lors d’une précédente thèse. Cependant, sa frontière interne est analytique et libre de chargement, ce qui rend difficile la connexion avec un élément rivet, et donc la modélisation de l’assemblage. L’étude proposée ici consiste donc à développer un super-élément perforé qui soit capable de tenir compte de l’influence de la perforation sur les champs mécaniques, d’une part, et qui soit formulé de façon à rendre possible l’interaction avec un macro-élément rivet, d’autre partThe thesis is made in a context which consists in improving the finite element (FE) analysis of full-scale aircraft structures subjected to crash and impact loadings. The study is focused, in particular, on the rivetedassemblies modeling in structural computations, which are stress concentrations areas where ruptures initiation can occur. If the fastener rupture is mastered, the rupture modes due to perforations are, however, difficult to simulate in a complete structure computation. In order to accurately take into account the perforations influence on the mechanical response of such structures, a perforated super-element featuring 8 nodes have been formulated in a previous thesis. Nevertheless, its internal boundary is analytic and free of loads, which makes difficult the connection with a rivet element, and consequently the assembly modeling. The study proposed here consists in the developement of a perforated super-element which is, on the one hand, able to take into account the perforation influence on the mechanical fields, and which is, on the other hand, formulated such as the interaction with a rivet macro-element is possible
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Langrand, Bertrand. "Contribution a la caractérisation numérique et expérimentale d'assemblages structuraux rivetés sous sollicitation dynamique." Valenciennes, 1998. https://ged.uphf.fr/nuxeo/site/esupversions/be7d3137-d768-41f5-89ac-e08bad40b081.
Abstract:
Dans le cadre de la conception des structures aéronautiques et de la modélisation de leur tenue mécanique, la représentation des comportements non linéaires locaux conduisant à la rupture est nécessaire et notamment ceux des liaisons. Ainsi en situation de crash survivable, les liaisons sont soumises à des charges dynamiques qui peuvent conduire à la rupture et à la désarticulation. Pour caractériser la tenue au crash des assemblages rivetés, une méthodologie dite de plans d'expérience numériques est proposée ; son intérêt est de limiter le cout des procédures expérimentales. Fondée sur les techniques de modélisation par éléments finis et d'optimisation par méthode inverse, la méthode repose sur la détermination des paramètres du comportement non linéaire et à la rupture des matériaux constitutifs de la liaison rivetée. Le développement de l'outil informatique d'optimisation est présenté dans la première partie du mémoire. Les modèles de comportement de deux alliages d'aluminium composant l'assemblage sont identifiés grâce à l'optimiseur. Ils seront utilisés pour mener les simulations de différents essais effectués sur les assemblages. L'évaluation des contraintes et des déformations résiduelles dues au procédé de rivetage est abordée dans la deuxième partie. Les mécanismes de mise en forme des rivets sont analyses expérimentalement. Des simulations sont d'autre part entreprises à l'aide du code de calcul explicite pam-solid#t#m, afin d'introduire, une fois validées, les contraintes et les déformations résiduelles post-rivetage dans le calcul de la tenue mécanique de l'assemblage. La faisabilité des plans d'expérience numériques est démontrée dans la troisième partie. Les paramètres d'endommagement du modèle de Gurson sont identifiés par méthode inverse pour les deux matériaux composant l'assemblage. La qualité de l'ensemble des résultats obtenus permet notamment d'envisager l'emploi de l'outil de simulation dans le cadre de la caractérisation de modèles équivalents macroscopiques du rivet. Ces techniques de modélisation simplifiée des liaisons sont abordées dans la dernière partie. Un critère de rupture de la liaison est caractérisé par l'expérience à l'aide du dispositif Arcan et par plan d'expérience numérique. Un nouveau modèle non linéaire de la liaison est développé dans le code de calcul pam-solid#t#m et ses paramètres identifiés. L'ensemble des résultats obtenus est finalement appliqué à la simulation de l'écrasement d'une structure comportant 700 rivets.
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Ali, Mohamad. "Assemblages structuraux des convertisseurs de puissance." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT003H/document.
Abstract:
L'accroissement des performances des équipements de Traction ferroviaire, reposait essentiellement jusqu'à maintenant, sur l'intégration des innovations dans le domaine des composants électriques et des matériaux diélectriques mais la standardisation de sous-ensembles réutilisables nous conduit à reconsidérer les assemblages structuraux des coffres de traction (convertisseurs de puissance). Ces coffres de traction sont assemblés actuellement avec des éléments de fixation mécanique (boulon, rivet), le but est donc d'améliorer la connaissance des comportements mécaniques de ces types d'assemblages à travers d'une étude expérimentale basée sur des essais statiques et dynamiques sur des joints boulonnés et rivetés. Ces essais nous ont permis de valider des modèles numériques par des éléments finis en utilisant les codes de calcul ABAQUS et ANSYS. La deuxième partie de la thèse concerne les assemblages par collage structural. Nous avons étudié la possibilité de remplacer les assemblages mécaniques classiques par l'assemblage par collage structural. La première phase de notre travail a été de recenser et sélectionner des adhésifs structuraux susceptibles de répondre à notre cahier de charge. Dans cette partie les travaux suivants ont été réalisés : - Etude des comportements des adhésifs en tant que matériau, ce qui a nécessité de réaliser des éprouvettes massiques. - Réalisation d'essais expérimentaux en statique et en dynamique sur des joints collés avec l'adhésif sélectionné. - Création des modèles numériques non linéaires en 3D sur ABAQUS pour les joints collés. - Etude hygrothermique accélérée afin d'étudier l'effet du vieillissement sur les assemblages collés en fonction de l'humidité et de la températureIncreased performance of railway traction equipment, until now relied primarily on the integration of innovations in the field of electrical and dielectric materials, but the standardization of subassemblies reusable us to reconsider the structural assemblies of the traction cubicles (power converters). These cubicles are assembled now with mechanical fasteners (bolts, rivets), the first goal is to improve knowledge of the mechanical behaviour of these types of joints through an experimental study based on statics and dynamics tests of bolted and riveted joints. These tests have allowed us to validate numerical models of finite elements by using the computer codes ABAQUS® and ANSYS®. The second part of the thesis deals with the structural adhesive joints. We studied the possibility of replacing conventional mechanical assembly structural bonding. The first phase of our work was to identify and select structural adhesives that could meet our specifications. In this section the following work has been made: - Study of thermo-mechanical behaviour of the adhesive with the bulk Adhesive Test Specimens. - Statics and dynamics test in the bonded joint. - Non-linear 3D finite elements models. - Hygrothermal accelerated to study the effect of aging on the adhesive according to the humidity and temperature
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Arbex, Alexandra Alvim [UNESP]. "Análise estrutural e de fadiga de juntas rebitadas de uso aeronaútico utilizando o método dos elementos finitos." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/97053.
Abstract:
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Juntas rebitadas sobrepostas representam elementos críticos na construção de estruturas aeronáuticas quando projetadas à fadiga. Por serem elementos de fixação largamente utilizados na indústria aeronáutica, o estudo de suas propriedades e variáveis à fadiga tem sido cada vez mais amplo. A variável que tem mostrado possuir alta influência na resistência à fadiga de juntas rebitadas é a força de aperto aplicada no processo de rebitagem. A vida da peça tende a ser maior quando o valor dessa força é aumentado. O método dos elementos finitos, que é uma ferramenta de cálculo aplicada nos mais diversos campos de atuação e tem se tornado parte indispensável de projetos mecânicos, é utilizado nesta dissertação para a análise de uma junta rebitada sobreposta de uso aeronáutico. A junta é simulada levando em conta as etapas do processo de fabricação e aplicação, a fim de realizar a análise de seu comportamento mecânico e calcular sua vida em fadiga. Através de um teste experimental de tração monotônica foram obtidos valores de deformação com extensômetros, e é feita a correlação desses dados com o modelo numérico a fim de validar a modelagem. Em seguida são feitas mais duas análises com diferentes forças de aperto, com o objetivo de verificar a influência dessa variação na vida em fadiga da peça.
Riveted lap joints represent a critical element in metallic airframe construction when designing against fatigue. These elements are widely used in the aerospace industry, so the study of the fatigue’s properties and variables has been increasingly broad. The variable that has shown to have a high influence on the fatigue strength of riveted joints is the clamping force applied to the riveting process. The life of the part tends to be higher when the clamping force applied is increased. The finite element method, which is a calculation tool applied in various fields of activity and has become an indispensable step of mechanical design, is used in this dissertation for the analysis of a riveted lap joint of aeronautic use. The joint is simulated considering the stages of the manufacturing process and application, in order to perform analysis of mechanical behavior and calculate the fatigue life. Through an experimental test of monotonic tensile, strain values were obtained with strain-gauges, and is made the correlation of these data with the numerical model to validate the modeling. Finally two more tests are made with different clamping forces, in order to check the influence of this variation in fatigue life of the joint.
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Ahmed, Abubaker Ali Tan Tein-Min. "Initiation and growth of multiple-site damage in the riveted lap joint of a curved stiffened fuselage panel : an experimental and analytical study /." Philadelphia, Pa. : Drexel University, 2007. http://hdl.handle.net/1860/1560.
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Victor, Clément. "Etude du comportement au feu d'assemblages titane-composite pour l'aéronautique." Electronic Thesis or Diss., Normandie, 2023. http://www.theses.fr/2023NORMIR38.
Abstract:
Le développement d’avions toujours plus légers avec une utilisation accrue de pièces composites à matrice polymère renforcée par des fibres de carbone soulève plusieurs questions concernant la sécurité à bord, notamment en matière de comportement des matériaux et des structures exposés au feu. En cas d'incendie dans l’environnement moteur d’un avion, les matériaux constituants les aérostructures sont soumis à des températures élevées et doivent répondre à des exigences de sécurité. Les composites à matrice organique ont un comportement thermique, chimique et mécanique très complexe qui, lorsqu'ils sont associés à des pièces métalliques très chaudes, peuvent remettre en question la capacité coupe-feu de ces structures. Ainsi, l’ambition majeure de ces travaux de thèse est de mieux comprendre le comportement au feu des assemblages titane-compositesThe development of increasingly lightweight aircraft with greater use of carbon fibre-reinforced polymer matrix composite parts raises a number of questions about on-board safety, particularly in terms of how materials and structures behave when exposed to fire. If a fire occurs in the engine environment of an aircraft, the materials constituting the aerostructures are subjected to high temperatures and must therefore meet safety requirements. Organic matrix composites have very complex thermal, chemical and mechanical behaviour that, when combined with very hot metal parts, could compromise the fireproofing capability of these structures. Thus, the major ambition of this thesis work is to gain a clearer understanding on the fire behaviour of titanium-composite assemblies
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Жигилій, Дмитро Олексійович, Дмитрий Алексеевич Жигилий, Dmytro Oleksiiovych Zhyhylii, С. Н. Демченко, and М. В. Акименко. "Розрахунок несучої здатності заклепкового з'єднання." Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/40257.
Abstract:
Заклепкові з‘єднання є нероз'ємними. Таке з‘єднання утворюють розклепуванням стержня заклепки, що вставлено в отвір деталі. При розклепуванні внаслідок пластичних деформацій утворюється замикальна
головка, а стержень заклепки заповнює зазор в отворі.
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Carunchio, André Ferrara. "Análise numérica e experimental de juntas aeronáuticas rebitadas sob solicitação estática." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3151/tde-12052016-144600/.
Abstract:
Uniões por prendedores são elementos amplamente utilizados na indústria aeronáutica para a união de partes constituintes da aeronave. Contudo, devido à sua geometria e aos carregamentos sofridos, estes elementos estão frequentemente sujeitos a falhas por fadiga. Assim, para um projeto e dimensionamento bem executado dessas juntas, é necessário conhecer seu comportamento mecânico e o campo de tensões ao qual estão sujeitas. O método dos elementos finitos certamente atende a estas necessidades; porém, o uso de elementos sólidos tridimensionais para a representação destas uniões pode levar a análises demasiadamente demoradas e custosas, sendo desejável o uso de modelos mais simplificados. Nesse trabalho, juntas de topo assimétricas são modeladas pelo método dos elementos finitos, utilizando tanto elementos sólidos tridimensionais quanto elementos de casca, com o objetivo de encontrar um modelo relativamente simples que apresente resultados satisfatórios e requeira um menor tempo de solução. Os resultados numéricos obtidos são comparados com resultados experimentais, que utilizam extensômetros e fotoelasticidade.Riveted joints are structural elements widely used in the aeronautic industry to connect different parts of the aircraft. However, due to their geometry and working load, they are frequently subjected to fatigue failure. Therefore, to a well executed project of this type of joint, it is necessary to understand the mechanical behavior and the stress field to which they are subjected. The finite element method can certainly answer those needs; however, the use of tridimensional elements to represent this type of joint can lead to time consuming and expensive analysis, being desirable the use of simpler models. In this work, asymmetric butt joints are modeled using the finite element method using both, tridimensional and shell elements, with the objective of finding a model that provides satisfactory results at smaller solution time. The numerical results obtained are compared with experimental results using strain gage and photoelastic procedures.
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Teixeira, Ritermayer Monteiro. "Metodologias para modelagem e análise da fadiga em ligações rebitadas com aplicação em pontes metálicas ferroviárias." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3144/tde-20072016-095317/.
Abstract:
O processo de fadiga em pontes metálicas ferroviárias é um relevante problema de infraestrutura, largamente reconhecido como uma questão de segurança estrutural que precisa ser melhor compreendida. Apesar dos recentes avanços no campo da modelagem computacional, a aplicação de abordagens modernas para avaliação do comportamento à fadiga de ligações rebitadas típicas de pontes ainda é pouco explorada e impõe desafios. Nesse contexto, esta tese visa implementar metodologias de análise global-local para avaliação de detalhes rebitados de pontes ferroviárias, empregando ferramentas avançadas de análise em elementos finitos para investigação pormenorizada do processo de fadiga. Com o objetivo de contextualizar o comportamento à fadiga de ligações rebitadas, apresentam-se inicialmente as principais metodologias convencionais de avaliação, destacando as limitações dos métodos. Apresentam-se também os principais aspectos da modelagem local em elementos finitos e das metodologias de análise local, enquadrando os regimes de comportamento onde cada abordagem pode ser aplicada. Exemplos em pequena escala são desenvolvidos para testar procedimentos numéricos e investigar a influência dos principais parâmetros que podem influenciar no comportamento local de ligações rebitadas, tais como modelos interfaciais de contato, fricção, pré-esforço nos rebites e distribuição interna de cargas. Análises de sensibilidade são realizadas tomando como referência uma ligação rebitada com uma trinca inicial pré-existente, onde tais efeitos são investigados. São descritos os procedimentos gerais de uma metodologia de modelagem desenvolvida para resolução de problemas que envolvem a integração contínua entre modelos globais e locais e um conjunto de ferramentas criadas para possibilitar o acoplamento entre o programa de simulação em elementos finitos e sub-rotinas customizadas programadas para processamento recursivo dos modelos e análise local da fadiga. A metodologia é então aplicada ao estudo dos detalhes rebitados de uma ponte real. A caracterização do comportamento global da ponte é realizada recorrendo-se aos resultados de simulações estáticas e dinâmicas e do monitoramento de curto prazo da estrutura. Também são apresentados resultados de estudos de sensibilidade e de previsão da vida à fadiga de detalhes críticos da ponte usando o método das tensões nominais e curvas SN baseadas em classes de detalhes. Diferentes aspectos são abordados, tais como a consideração dos efeitos secundários de flexão nas ligações e a influência do tipo de veículo e da configuração do trem. Por último, é realizada uma análise local das ligações rebitadas da ponte ferroviária tomada como estudo de caso. Modelos tridimensionais detalhados das conexões são desenvolvidos em duas etapas. Na primeira são aplicadas técnicas de modelagem hierárquica para avaliar de forma pormenorizada os mecanismos de transferência de cargas entre os membros envolvidos, os efeitos secundários de flexão e a influência de diferentes hipóteses de modelagem. Na segunda etapa, são desenvolvidos submodelos com elementos sólidos e altas densidades de malhas para investigação dos campos de deformações e tensões locais nas regiões apontadas como críticas durante a modelagem hierárquica. As geometrias dos rebites são representadas explicitamente e todas as interações de contato são modeladas. A influência do pré-esforço nos rebites é avaliada. As abordagens ?N e SN são aplicadas para enquadrar o regime de fadiga das ligações, verificar critérios de falha incluindo tensões multiaxiais e fazer previsões da vida de iniciação da trinca. São apresentados os principais resultados das análises bem como as conclusões que corroboram a metodologia empregada.The fatigue process in steel railway bridges is an important problem of infrastructure, widely recognized as an issue of structural safety that needs to be better understood. Despite the recent advances in computational modeling, application of modern approaches to fatigue assessment of typical riveted bridges is still little investigated and poses challenges. In this context, this thesis aims to implement some methodologies for global-local analyses in riveted details of steel railway bridges using advanced finite element analysis tools for a deep investigation of the fatigue process. In order to contextualize the fatigue behavior of riveted connections, the conventional assessment procedures are initially presented, highlighting the limitations of the methods. The main points of the local finite element modeling and of the local analysis methods are also described, defining the regimes where each approach can be applied. Examples on a small scale to test numerical procedures are developed and the influence of the main parameters that can influence the local behavior of riveted connections is investigated, such as contact interfacial models, friction, clamping force in rivets and internal load distribution. Sensitivity analyses with reference to a riveted connection with a pre-existing initial crack are performed, where such effects are investigated. The general procedures of a modeling methodology developed for problem solving that involves the seamless integration between global and local models and a set of tools created to enable coupling between the finite element simulation program and customized subroutines to recursive processing and fatigue local analysis of the models are described. Then, the methodology is applied to the study of riveted details of a railway bridge. The global behavior of the bridge is performed based on the results of static and dynamic simulations and from short-term monitoring data. The results of sensitivity studies and fatigue life predictions using the nominal stress method and detail class SN curves for critical details of the bridge are also presented. Different aspects, such as the consideration of bending secondary effects at connections and the influence of the vehicle types and train configurations are addressed. Finally, a local analysis is carried out in the riveted railway bridge taken as a case study. Three-dimensional models, detailing the connections in two stages are developed. The first hierarchical modeling techniques are applied to assess the load distribution mechanisms between the members involved, the bending secondary effects and the influence of different modeling assumptions. In the second stage, sub-models with solid elements and high mesh densities for investigation of strain and stress fields in the regions identified as critical by the hierarchical model are developed. The geometries of the rivets are explicitly represented and all contact interactions are modeled. The influence of rivet clamping forces is evaluated. The ?N and SN local approaches are applied to define the fatigue regime in critical points, check failure criteria in multi-axial stresses and to predict the crack initiation life. The main results of the analyses and the conclusions that support the methodology are presented.
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Soares, Henrique Nogueira. "Detecção por raios-x de trincas de fadiga em juntas rebitadas de Glare®." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-09042008-150513/.
Abstract:
Foi realizado um estudo comparativo da capacidade de duas variantes do método de radiografia por raios- X em detectar trincas de fadiga em juntas sobrepostas rebitadas de laminado híbrido metal-fibra Glare® de uso aeronáutico. Durante os ensaios mecânicos de fadiga sob amplitude constante de tensão, diversos corpos de prova rebitados foram periodicamente inspecionados por raios-X, em ambas as modalidades convencional e digital. Raios-X em filmes convencionais digital. Raios-X em filmes convencionais proporcionaram ótimo detalhamento de trincas nas juntas mecânicas, enquanto que as imagens geradas pela modalidade digital apresentaram qualidade muito inferior, prejudicando ou até mesmo impedindo a avaliação do grau de integridade estrutural das juntas rebitadas.A comparison is performed on the ability of two modalities of nondestructive X-ray radiography method in detecting fatigue cracks in riveted lap joints of aeronautical grade fiber-metal laminate Glare™. During constant amplitude loading in fatigue testing riveted specimens were periodically inspected using both the conventional and digital X-ray methodology. Conventional film X-ray modality provided high quality images of growing cracks in the mechanical joints, whereas digital radiography generated faulty images, which impaired or even prevented the structural integrity assessment of the riveted joints.
37
Adámek, Petr. "Kritéria hodnocení únavové životnosti nýtových spojů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232022.
Abstract:
This thesis describes proposal of a methodology for evaluating fatigue life of riveted joints. The first section summarizes the theory used to evaluate fatigue life, description of the structure of operation load spectra and construction principles for the design joints for optimum durability. The second part of the thesis focuses on the proposal of a methodology enabling analytical solutions in closed form suitable for the initial structural design and also numerical solutions for use in detailed analyzes of the structure. The applicability of the methodology is demonstrated on an example of analysis of a real structural detail and subsequent comparison of the analysis with available test results.
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Zakrisson, Axel. "Jacques Rivette : en båttur genom hans auteurskap." Thesis, Högskolan i Gävle, Avdelningen för humaniora, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-12741.
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Plathe, Kelly Lee. "Nanoparticle - Heavy Metal Associations in Riverbed Sediments." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/26229.
Abstract:
Relationships between trace metals and nanoparticles were investigated using analytical transmission electron microscopy (aTEM) and asymmetric flow field flow fractionation (aFlFFF) coupled to both multi-angle laser light scattering (MALLS) and high resolution-inductively coupled plasma mass spectroscopy (HR-ICPMS). Riverbed sediment samples were taken from the Clark Fork River in Montana, USA where a large-scale dam removal project has released reservoir sediment contaminated with toxic trace metals (namely Pb, Zn, Cu and As) which accumulated from one and a half centuries of mining activities upstream. An aqueous extraction method was used to attempt to separate the nanoparticles from the bulk sediment. After analysis of initial results, it was found that low density clays were being selected for in this process and made up a major portion of the particles within the extracts. However, it was also realized that the metals of interest were associated almost exclusively with nano-sized Fe and Ti oxides.
In order to more fully examine these relationships, a density separation method, using sodium polytungstate (2.8g/cm3), was developed to separate these higher density oxides from the lower density clays. The heavy fraction was then subjected to an aqueous extraction routine to extract the nanoparticulate fraction. FFF results indicated a smaller size distribution and more ideal fractionation with this method. The aFlFFF-HR-ICPMS profiles for Fe and Ti also matched strongly with the data for the trace metals. The majority of particles analyzed with the TEM were nano-sized Fe and Ti oxides (most commonly goethite, ferrihydrite and brookite), which typically had trace metals associated with them. In many cases, it was aggregates of these nano oxides that were found hosting trace metals. Nanoparticles and aggregates are known to behave differently than their bulk mineral phases or constituent particles, respectively. Nanoparticles are also capable of extended transport in the environment. For these reasons, it is important that their associations with toxic trace metals be extensively evaluated, as they will affect the bioavailability and toxicity of these metals with implications for any type of contaminant sediment relocation, dam removal or metal contaminated site.Ph. D.
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Lojek, Stanislav. "Návrh laboratorních úloh v prostředí Riverbed Modeler." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-376978.
Abstract:
This semestral thesis deals with the creation of a laboratory exercise for the course of Communication Technology. This course is designed for Teleinformatics in bachelor's degree program and should provide students with basic knowledge of network protocols and technologies. For this reason, the thesis deals with basic transport protocols, protocols for transmission via backbone networks and network layer protocols. The introductory part introduces the OPNET design environment, more precisely its free version of Riverbed Modeler Academic Edition 17.5, where the design of the laboratory exercises is done. The second part is a necessary theory to the exercises. The lab exercise is focused on differences in TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) protocols. The second laboratory exercises is focused on technologies for transmission mainly on WAN (Wide Area Network) namely ATM (Asynchronous Transfer Mode) and Frame Relay. The last proposed exercises deals with the two most prominent Internet protocols that are used for communications IPv4 (Internet Protocol version 4) and IPv6 (Internet Protocol version 6) protocols. Guides for students have been created for this task, and at the end of each part, the complementary tasks and questions are given to students in oder to test the gained knowledge of the discussed issues.
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Makings, Elizabeth, Lane Butler, Matthew Chew, and Juliet Stromberg. "Noteworthy Collections from Tempe Town Lake Riverbed." University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/556794.
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Santillán, Richard. "Rosita the Riveter: Midwest Mexican American Women During World War II, 1941-1945." Mexican American Studies & Research Center, The University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/623019.
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Bayart, Anne-Sophie. "Modélisation multi-échelle d'un assemblage riveté aéronautique, vers un modèle de fragilisation structurale /." Châtillon : ONERA, 2006. http://catalogue.bnf.fr/ark:/12148/cb40115847x.
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Kaffel, Hedi. "Étude expérimentale du comportement vibratoire des structures rivetées." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq21773.pdf.
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Kaffel, Hédi. "Étude expérimentale du comportement vibratoire des structures rivetées." Mémoire, Université de Sherbrooke, 1996. http://savoirs.usherbrooke.ca/handle/11143/988.
Abstract:
Le présent travail s'inscrit dans ce cadre et propose de quantifier les effets des liaisons mécaniques sur le comportement vibratoire des structures semi-complexes. Ce document traite expérimentalement le comportement vibratoire des structures finies et liées par des rivets à un raidisseur avec des conditions aux limites de type simplement appuyé sur les bords. Ce travail a été réalisé sur plusieurs étapes. La première consiste à trouver le montage expérimental adéquat pour pouvoir faire l'analyse vibratoire des structures jusqu'à des hautes fréquences. Ce montage servira à la mesure de la vitesse quadratique d'une plaque simple de dimensions finies et soumise à une excitation mécanique mesurée. Les prédictions de plusieurs modèles théoriques sont comparées aux résultats expérimentaux de ce montage. La deuxième étape consiste à étudier expérimentalement le comportement vibratoire d'une structure rivetée tout en gardant les mêmes caractéristiques géométrique et mécanique de la structure que la première étape. Cette dernière étape a été faite en deux parties. La première est d'effectuer expérimentalement la mesure vibratoire d'une structure avec un faible nombre de rivets. Les mêmes expériences ont été reproduites sur une même structure avec un nombre élevé de rivets. Ces résultats sont comparés à ceux trouvés dans la première étape. La troisième partie consiste à mesurer expérimentalement le comportement vibratoire d'une structure raidie de mêmes dimensions que la première avec les mêmes conditions aux limites. La dernière étape de ce travail consistera en l'étude expérimentale du comportement vibratoire d'une structure, de même caractéristiques géométriques et mécaniques, assemblée à un raidisseur aux moyens de rivets avec des conditions aux limites de type simplement appuyé. Ces résultats seront comparés à ceux trouvés dans la deuxième et troisième étapes.
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Dosi, Francesca. "Trajectoires balzaciennes dans le cinéma de Jacques Rivette : Out1 - La belle noiseuse - Ne touchez pas à la hache." Thesis, Paris 3, 2013. http://www.theses.fr/2013PA030008.
Abstract:
Cette étude suit les trajectoires balzaciennes qui parcourent l'oeuvre de Jacques Rivette, en créant un réseau complexe de références, d'allusions et de citations qui reflètent la construction en toile d'araignée de La Comédie Humaine. Elles irriguent trois réalisations ouvertement inspirées de Balzac : Out 1, Noli me tangere (1970-71), film fleuve expérimental d'environ treize heures, articulé sur l'improvisation des acteurs et centré sur la quête des Treize balzaciens, La Belle Noiseuse (1991) qui transpose au présent du tournage l'histoire du Chef d’oeuvre inconnu en la modifiant partiellement, et Ne touchez pas la hache (2007), film en costume « fidèle à la lettre » à La Duchesse de Langeais. Out 1 mêle le récit énigmatique balzacien à la flânerie surréaliste pour interroger la mythologie du groupe et l'onirisme psychédélique des années soixante-dix. La Belle Noiseuse offre à Rivette l'occasion de mettre en scène le processus de création - les séances de pose - et de réfléchir simultanément à son travail de cinéaste et à l'entreprise démesurée de La Comédie Humaine. La « compression à la César » à laquelle il soumet La Duchesse de Langeais fait de Ne touchez pas la hache un traité métaphysique intemporel sur l'empêchement amoureux, mais aussi une méditation sur la philosophie balzacienne et sur la théâtralité propre à La Comédie Humaine. Entre reprise et transformation, Jacques Rivette réalise donc trois oeuvres différemment marquées par une puissante innutrition balzacienne, les inscrivant dans un parcours inhabituel d’assimilation,d’hybridation et de réinvention du fait littéraire au cinémaThis thesis follows the traces of Balzac’s presence in Jacques Rivette’s output and of thecomplex network of references, allusions and quotations that create a mirror image of thecobweb-like structure of the Comédie Humaine. These traces emerge particularly in threeworks overtly inspired by Balzac : Out 1, Noli me tangere (1970-71), an experimental filmfleuve approximately 13 hours long, built on actorial improvisation and centred on atransposition of the quest of Balzac’s Treize to contemporary times; La Belle Noiseuse (1991)which transposes and partly modifies the narrative of Le Chef-d’Oeuvre inconnu to thepresent of the filming process; and Ne touchez pas la hache (2007), a costume (and thus‘literally faithful’) reprise of La Duchesse de Langeais. Out 1 mixes surrealist flanerie toBalzac’s enigmatic narration in order to question the myth of the select group and thepsychedelic oneirism typical of the 1960s. As dramatisations of a novelistic ellipsis, themodel’s sittings in La Belle Noiseuse offer Rivette the opportunity to stage the process ofartistic creation and, at the same time, to reflect on his work as a filmmaker and on theenormous project of the Comédie Humaine. The “César-style” compression to which hesubmits La Duchesse de Langeais turns the narrative into an atemporal metaphysical treatiseon a lover’s impasse, as well as into the occasion for a meditation on Balzac’s philosophy andthe theatricality typical of the Comédie Humaine. Caught up between reprise andtransformation, Jacques Rivette’s films constitute as many re-elaborations that are, to differentdegrees, impregnated with Balzac’s powerful oeuvre, and thus delineate an original set offorms of assimilation, hybridisation and reinvention of literary texts on screen
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Whiteleather, Hagan Faye. "FROM RIVETER TO RIVETING: THE REBIRTH OF THE FEMME FATALE IN POST-WAR AMERICA." Kent State University Honors College / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1431360238.
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Jardonnet, Évelyne. "Poétique de la singularité au cinéma : une lecture croisée de Jacques Rivette et de Maurice Pialat /." Paris ; Budapest ; Kinshasa [etc.] : l'Harmattan, 2006. http://catalogue.bnf.fr/ark:/12148/cb40238864t.
Abstract:
Texte remanié de: Thèse de doctorat--Arts du spectacle--Paris 10, 2003. Titre de soutenance : Poétique de la singularité au cinéma : l'exemple de Jacques Rivette et de Maurice Pialat.Bibliogr. p. 307-315. Index.
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Ralph, William Carter. "Assessment of hole drilling procedures on resulting fatigue lives." Thesis, Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04072004-180146/unrestricted/ralph%5Fwilliam%5Fc%5F200312%5Fms.pdf.
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Hyodo, Makoto. "Ecological Evaluation of Shifting Habitat History for Riverbed Management." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/202698.