Sammanfattning Examensarbetet behandlar analys och beräkning av ett modifierat cykelnav vilket är tänkt att sitta på en rullstol samt design och materialförslag för hjul. Utgångsläget var ett på marknaden idag vanligt förekommande cykelnav som bearbetats för att passa de krav en rullstolsanvändare ställer på produkten. T.ex. är frihjulsfunktionen hos cyklar ej önskvärd hos rullstolar och därför borttagen. Målet för uppdragsgivaren Gearwheel AB är att konstruera ett hjul där inget annat skiljer sig från dagens förutom växlarna. Känslan skall vara identisk med dagens hjul i fråga om greppringens geometri, glapp och vibrationer. Rullstolsnavet antogs vara överdimensionerat och analyser av respektive växlar modellerades och beräknades i ABAQUS. Detta för att hitta alternativa material och omkonstruktioner för att minimera vikten på navet, då detta är av stort intresse för företaget i säljsyfte. Navet innebär ovillkorligen en viktökning jämfört med oväxlade nav som endast består av en enkel axel. Beräkningarna visade dock att vridmomentet som påverkar växlarnas ingående delar inte skilde sig markant från cykelns, vilket innebar att hållfastheten på materialet inte kunde ändras nämnvärt. Detta begränsade materialvalet till liknande det rostfria stål som orginalnavet var konstruerat av och titan. Titan är dock en dyr och exklusiv metall som ansågs som mindre trolig som konstruktionsmaterial. Möjlighet för alternativa material fanns i navets ytterhölje då detta inte var lika kraftpåkänt som de inre rörliga delarna. Därför gjordes designförslag på hjulet som helhet enligt de vanligt förekommande produktutvecklingsmetoderna. / Abstract This master thesis considers the analysis and calculation of a modified bicycle hub, intended for a wheelchair, including design and material suggestions for the wheel. The initial hub was a common bicycle hub, which had been worked on to accommodate the demands of a wheelchair user. The bicycles function of free wheel is not desirable and therefore taken out of the construction. The goal of the principal Gearwheel AB is to design a wheel, where nothing else differs from the current, than the gearing system. The feel of the wheel should be identical to the current regarding the geometry, play and vibration of the grip ring. The gear wheel hub was assumed to be over dimensioned, and therefore analysis’s for each gear was modelled and calculated using ABAQUS. This was done for the purpose of finding alternative materials and reconstructions to minimize the weight of the hub. This was of great interest of the company for selling purposes. The hub is undoubtedly adding weight to the wheel compared to an ordinary wheel with just a single axle. The calculations however showed that the torque affecting the gear parts did not differ much from the bicycle, which meant that material’s strength could not be changed to a greater extent. This restricted the material choice to materials similar to the existing stainless steel or titanium. Titanium, however, is an expensive and exclusive material and the use of it was considered limited. The possibility of alternative materials was found in the cover of the hub, for the reason of lower strength demands than the inner parts of the hub. Therefore design suggestions were made for the entire wheel according to the common product development theories.

<p>Sammanfattning</p><p>Examensarbetet behandlar analys och beräkning av ett modifierat cykelnav vilket är tänkt att sitta på en rullstol samt design och materialförslag för hjul.</p><p>Utgångsläget var ett på marknaden idag vanligt förekommande cykelnav som bearbetats för att passa de krav en rullstolsanvändare ställer på produkten. T.ex. är frihjulsfunktionen hos cyklar ej önskvärd hos rullstolar och därför borttagen. Målet för uppdragsgivaren Gearwheel AB är att konstruera ett hjul där inget annat skiljer sig från dagens förutom växlarna. Känslan skall vara identisk med dagens hjul i fråga om greppringens geometri, glapp och vibrationer.</p><p>Rullstolsnavet antogs vara överdimensionerat och analyser av respektive växlar modellerades och beräknades i ABAQUS. Detta för att hitta alternativa material och omkonstruktioner för att minimera vikten på navet, då detta är av stort intresse för företaget i säljsyfte. Navet innebär ovillkorligen en viktökning jämfört med oväxlade nav som endast består av en enkel axel.</p><p>Beräkningarna visade dock att vridmomentet som påverkar växlarnas ingående delar inte skilde sig markant från cykelns, vilket innebar att hållfastheten på materialet inte kunde ändras nämnvärt. Detta begränsade materialvalet till liknande det rostfria stål som orginalnavet var konstruerat av och titan. Titan är dock en dyr och exklusiv metall som ansågs som mindre trolig som konstruktionsmaterial.</p><p>Möjlighet för alternativa material fanns i navets ytterhölje då detta inte var lika kraftpåkänt som de inre rörliga delarna. Därför gjordes designförslag på hjulet som helhet enligt de vanligt förekommande produktutvecklingsmetoderna.</p> / <p>Abstract</p><p>This master thesis considers the analysis and calculation of a modified bicycle hub, intended for a wheelchair, including design and material suggestions for the wheel.</p><p>The initial hub was a common bicycle hub, which had been worked on to accommodate the demands of a wheelchair user. The bicycles function of free wheel is not desirable and therefore taken out of the construction. The goal of the principal Gearwheel AB is to design a wheel, where nothing else differs from the current, than the gearing system. The feel of the wheel should be identical to the current regarding the geometry, play and vibration of the grip ring.</p><p>The gear wheel hub was assumed to be over dimensioned, and therefore analysis’s for each gear was modelled and calculated using ABAQUS. This was done for the purpose of finding alternative materials and reconstructions to minimize the weight of the hub. This was of great interest of the company for selling purposes. The hub is undoubtedly adding weight to the wheel compared to an ordinary wheel with just a single axle.</p><p>The calculations however showed that the torque affecting the gear parts did not differ much from the bicycle, which meant that material’s strength could not be changed to a greater extent. This restricted the material choice to materials similar to the existing stainless steel or titanium. Titanium, however, is an expensive and exclusive material and the use of it was considered limited.</p><p>The possibility of alternative materials was found in the cover of the hub, for the reason of lower strength demands than the inner parts of the hub. Therefore design suggestions were made for the entire wheel according to the common product development theories.</p>

The aim of this thesis paper, to create a numerical model to examine the residual stresses induced by orthogonal machining in the finished work piece and the model is validated by comparing with experimental result. The finite element method is used to simulate and analyze the residual stresses induced by a orthogonal metal cutting process. A Dynamics explicit time integration technique with Arbitrary Lagrangian Eulerian (ALE) adaptive meshing Finite Element Method (FEM) is employed to simulate the model. The Johnson-Cook material model is used to describe the work material behaviour and fully coupled thermal-stress analysis are combined to realistically simulate high speed machining with an orthogonal cutting. Finite Element modelling of Residual stresses and resultant surface properties induced by round edge cutting tools is performed as case studies for high speed orthogonal machining of 20NiCrMo5 steel. As a conclusion we can say that results from 2D simulations are very close to the experimental results at the surface level, but there is bit difference when we go down in the material. In 3D simulation, results agree with the experimental values in all levels So we can say that it is possible to model residual stresses, induced by orthogonal machining with accepted amount of accuracy. Keywords Residual stress, FE-modelling, ALE formulation,3D.ABAQUS/CAE / FEM,ALE, ABAQUS

En raison de leurs excellentes propriétés spécifiques, les matériaux composites à matrice organique sont de plus en plus utilisés dans le secteur des transports. Durant leur vie en service, ces matériaux composites sont souvent soumis à des environnements hygroscopiques agressifs. Dès la phase transitoire du p processus de diffusion, l’absorption d’eau engendre des variations dimensionnelles ainsi que la plastification du réseau polymère, ce qui modifie son comportement mécanique. Ce travail est dédié à la caractérisation expérimentale des lois de comportement hygro-mécaniques des matériaux étudiés au cours d’un vieillissement humide. Des méthodes d’analyse numérique permettent d’identifier l’évolution de certaines propriétés matériaux dans la phase transitoire du processus. Parmi ces propriétés, une attention particulière est portée au coefficient de gonflement hygroscopique et au module de traction. Afin de simuler les observations expérimentales, on a mis en place un modèle multi-physique et multi-échelle tenant compte, non seulement du gonflement hygroscopique local au cours de la p hase transitoire de diffusion de l’humidité, mais aussi de la diminution du module élastique. Par ailleurs, les modèles hygro-mécaniques proposés sont étendus au cadre stochastique afin de considérer les incertitudes expérimentales. Les modèles sont implémentés dans le code éléments finis Abaqus® afin de réaliser des simulations numériques prédisant les champs de teneur en eau ainsi que les états mécaniques internes. L’approche proposée est validée sur la base des résultats expérimentaux et plusieurs études numériques sur le polyamide seul ou sur des composites sont présentées. / Due to their excellent specific properties, composite materials with organic matrix are increasingly used in transport industry. During their lifetime, these materials can be subjected to aggressive hygroscopic environments. The moisture especially induces the plasticization of the polymer network, which affects its mechanical behavior, as well as dimensional changes occurring during the diffusion process. The purpose of this work is to experimentally characterize the hygro-mechanical behavior of the studied materials during aging under relative humidity conditions. Numerical analysis methods are implemented in order to identify the evolution of material properties during the transient stage of the process. Among these quantities, the present work consists in characterizing the hygroscopic expansion coefficient and the tensile modulus. It will be established that, in order to appropriately reproduce the experimental, it is necessary to develop a multi-physics and multi-scale approach accounting for the local swelling experienced by the polymer during the transient stage of the moisture diffusion process, as well as the decreasing of the elastic modulus. Moreover, some of the proposed hygromechanical models have been extended to the stochastic framework in order to take into account the experimental uncertainties. The proposed models are implemented in the finite element software Abaqus® enabling to perform numerical simulations leading to predictions of the moisture fields and the internal mechanical states. The proposed approach has been validated with the experimental data and several numerical studies involving neat polyamide resin and composites are proposed.

Due to the constraint of high costs and limitations of load conditions, experimental testing is not appropriate for the static study of shelter structures. Comparatively, an effective computational modeling and numerical solution demonstrates significant advantages for understanding the response of steel shelter structures. This study gives an insight into the structural integrity of the prototype shelter structure which is examined using computer simulation of the shelter structure on Abaqus/CAE 2019. The results of the computer modelling demonstrate the response of shelter structure under ten different loading conditions as per ISO 1496:2013 (E). The loading conditions are applied to various components of the shelter structure and corresponding deflection are observed.

[pt] A presença de estruturas salinas ao redor do mundo em águas profundas do golfo do México, do Brasil, de Angola, do norte e do oeste da África forma condições favoráveis para o aprisionamento dos hidrocarbonetos e aumenta a probabilidade de sucesso na prospecção de óleo e gás. Na Bacia de Santos, por exemplo, foram divulgadas recentemente novas descobertas de óleo abaixo de uma espessa camada salina. Por outro lado, muitos problemas operacionais, como o aprisionamento de coluna de perfuração e o colapso do poço, têm sido registrados pela indústria do petróleo quando se está perfurando através de espessas camadas de sal. Estes contratempos criam grandes desafios e geram oportunidade de evolução da Indústria do Petróleo. Desta forma, esta dissertação propõe um estudo do comportamento mecânico do sal em poços de petróleo. Analisaram-se os deslocamentos, deformações e tensões na parede do poço e em sua vizinhança para diversos pesos de fluido de perfuração com a utilização do método dos elementos finit os. Foram realizadas modelagens computacionais mediante o uso de um programa comercial de elementos finitos: o Abaqus. Através de análises de deformação plana e análises axissimétricas, estas simulações numéricas puderam prever o comportamento elástico e, principalmente, o de fluência (creep) do sal. Sendo assim, como contribuição técnica, este estudo auxilia o controle e o monitoramento do fechamento de poços de petróleo em estratos salinos, evitando deste modo, diversos problemas causados pelo comportamento de fluência do sal, como o colapso do poço. Com isso, é fundamental a inclusão das análises das seções salinas nos projetos de perfuração de poços de petróleo. No que diz respeito ao quesito econômico, a principal contribuição deste trabalho é a redução do tempo de intervenções do poço provocadas por problemas ocorridos em camadas de sal e, conseqüentemente, a redução do tempo necessário para perfuração do poço e a diminuição do tempo de aluguel da sonda. / [en] The presence of saline structures around the world, in deepwater like the ones of the Mexican Gulf, Brazil, Angola, North and West Africa, provides favorable conditions for hydrocarbons imprisonment. It increases the probability of success in oil and gas exploration. In the Santos Basin, for example, it was recently noticed that a light crude oil located below a thick salt layer was discovered. On the other hand many operational problems in salt drilling like the imprisonment of the drillstring and closing of the well have been registered in the industry. These types of problems create big challenges in the oil industry and at the same time opportunities for the evolution of the drilling technology. This work proposes the study of the mechanical behavior of salt in oil wells. Dislocations, strains and stresses were analyzed in the face of the wellbore and into the salt formation by finite element analysis. Several finite element analyses were developed to represent the possible scenarios in salt drilling using a program denominated Abaqus. These numerical simulations were analyzed through plane strain and axisymmetric techniques, could predict elastic and specially creep behavior. As a technical contribution, this study helps to avoid wellbore closure and casing collapse of salt sections, adding to the wellbore and drilling project an accurate salt section analysis and preventing workover operations due to salt mass deformation. Finally the economical contribution of this study is the reduction of workover time and of expenses in salt sections drilling. By reducing workover time, there is a notorious decrease in rig time use.

This master thesis has its main focus within embossing operations and how different factors influence the result. The work was performed at Stora Enso Research Centre in Karlstad, Sweden. Embossing is relatively complex operation to analyze since the paperboard can be exposed of both bending, shear and compression at the same time. The techniques used today for evaluating embossing on paperboard consist of experimental setups. These experimental techniques needed to be complemented in order to simplify the approach for embossing evaluations. The aim of this thesis was to develop a simulation material model, created with Finite Element Method by using Abaqus (2014), which capture the experimental behavior of embossed paperboard. The goals were to understand which material properties that are of high importance in embossing operations, and how sensitive the simulation material model is at small geometry changes of the embossing tool. A three dimensional finite element material model has been created in Abaqus (2014). The analysis was performed as dynamic quasi-static where an implicit solver was used. The simulation material model consisted of a continuum model, which describes the behavior of the plies, and an interface model implemented as cohesive elements, which describes the inelastic delamination between the plies. The continuum model was defined as an anisotropic linear elastic-plastic material model with isotropic linear hardening together with Hill´s yield criterion. The interface model was defined with an anisotropic elastic-plastic traction-separation law and an exponential damage evolution model. The purpose of the experimental tests was to capture the behavior of embossed paperboard and the goal was then to recreate the behavior in the simulation model. The results in this thesis focus on the relationship between the applied force and the displacement. An experimental and numerical study of out-of-plane compression has also been conducted, where the aim was to determine the out-of-plane elastic modulus, EZD. According to embossing results, the embossing results showed an exponential hardening behavior while the numerical results, unfortunately, showed a declining hardening behavior. Despite this, some understanding regarding which parameters that are of utmost importance have been achieved. The material parameters which had the highest influence on embossed paperboards seem to be the out-of-plane shear properties. This thesis also shows that the material model is sensitive of small changes of the tool geometry. The proportion of shear, bending and compression are strongly dependent on if the tool has sharp edges or if the edges are more rounded.

The objective of this research was to develop and verify a mathematical model that enables the prediction of the effects of heat treatment on cast aluminum alloy components. The model, which uses the commercially available software (ABAQUS), predicts dimensional changes, distortion, and residual stresses in heat treated components. An extensive database is developed for an example aluminum alloy (A356) and includes the mechanical, physical, and thermal properties of the alloy all as functions of temperature. The database is obtained through calculations and measurements made on A356 alloy specimens. In addition, boundary conditions ¨C in the form of heat transfer coefficients for each of the heat treatment steps - are obtained from measurements performed with a special quenching system developed at the Center for Heat Treating Excellence at WPI. The database and boundary conditions were used in the software to predict the dimensional changes, distortions, and residual stresses that develop in a commercial A356 cast component that is subjected to a standard commercial heat treating cycle. In order to verify the accuracy of the software predictions, the predictions were compared to their measured counterparts, where dimensional changes and distortion were measured with a coordinate measuring machine, and residual stresses were measured with x-ray diffraction.

The panel zone region in columns of seismic resistant steel moment frames are subject to very high shear forces during earthquake loading. Doubler plates are often used to increase the stiffness and strength of the panel zone. The methods and details used to attach doubler plates to columns can affect seismic performance of the panel zone and can also affect cost. The research reported in this thesis was aimed at developing an improved understanding of the advantages and disadvantages of various approaches for detailing and welding doubler plates to columns and how various details perform under cyclic inelastic loading. An extensive series of finite element analyses were conducted to study doubler plate attachment details. Both a shallow W14x398 column and a deep W40x264 column were studied in this research. This thesis provides a detailed description of the finite element modeling techniques used for the research and presents the results of an extensive series of analyses examining a wide variety of issues related to doubler plate design and detailing. / text

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