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Finite element modeling of straightening of thin-walled seamless tubes of austenitic stainless steelJohansson, Robert January 2016 (has links)
During this thesis work a coupled thermo-mechanical finite element model (FEM) was builtto simulate hot rolling in the blooming mill at Sandvik Materials Technology (SMT) inSandviken. The blooming mill is the first in a long line of processes that continuously or ingotcast ingots are subjected to before becoming finished products. The aim of this thesis work was twofold. The first was to create a parameterized finiteelement (FE) model of the blooming mill. The commercial FE software package MSCMarc/Mentat was used to create this model and the programing language Python was used toparameterize it. Second, two different pass schedules (A and B) were studied and comparedusing the model. The two pass series were evaluated with focus on their ability to healcentreline porosity, i.e. to close voids in the centre of the ingot. This evaluation was made by studying the hydrostatic stress (σm), the von Mises stress (σeq)and the plastic strain (εp) in the centre of the ingot. From these parameters the stress triaxiality(Tx) and the hydrostatic integration parameter (Gm) were calculated for each pass in bothseries using two different transportation times (30 and 150 s) from the furnace. The relationbetween Gm and an analytical parameter (Δ) was also studied. This parameter is the ratiobetween the mean height of the ingot and the contact length between the rolls and the ingot,which is useful as a rule of thumb to determine the homogeneity or penetration of strain for aspecific pass. The pass series designed with fewer passes (B), many with greater reduction, was shown toachieve better void closure theoretically. It was also shown that a temperature gradient, whichis the result of a longer holding time between the furnace and the blooming mill leads toimproved void closure.
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Finite element analysis of hot rolling in the blooming millPersson, Petter January 2016 (has links)
During this thesis work a coupled thermo-mechanical finite element model (FEM) was builtto simulate hot rolling in the blooming mill at Sandvik Materials Technology (SMT) inSandviken. The blooming mill is the first in a long line of processes that continuously or ingotcast ingots are subjected to before becoming finished products. The aim of this thesis work was twofold. The first was to create a parameterized finiteelement (FE) model of the blooming mill. The commercial FE software package MSCMarc/Mentat was used to create this model and the programing language Python was used toparameterize it. Second, two different pass schedules (A and B) were studied and comparedusing the model. The two pass series were evaluated with focus on their ability to healcentreline porosity, i.e. to close voids in the centre of the ingot. This evaluation was made by studying the hydrostatic stress (σm), the von Mises stress (σeq)and the plastic strain (εp) in the centre of the ingot. From these parameters the stress triaxiality(Tx) and the hydrostatic integration parameter (Gm) were calculated for each pass in bothseries using two different transportation times (30 and 150 s) from the furnace. The relationbetween Gm and an analytical parameter (Δ) was also studied. This parameter is the ratiobetween the mean height of the ingot and the contact length between the rolls and the ingot,which is useful as a rule of thumb to determine the homogeneity or penetration of strain for aspecific pass. The pass series designed with fewer passes (B), many with greater reduction, was shown toachieve better void closure theoretically. It was also shown that a temperature gradient, whichis the result of a longer holding time between the furnace and the blooming mill leads toimproved void closure.
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Contribution à l'étude de l'essai de rayage des verres / A contribution to the modeling of the scratch test response of glassesLe, Ngoc Hiep 25 November 2013 (has links)
Ce travail de thèse contribue à étudier le comportement élasto-plastique au rayage du verre métallique massif Zr55Cu30Al10Ni5 par la méthode des éléments finis (MEF) et expérimentaux. Le critère de plasticité de type Drucker-Prager est utilisé, une méthode de remaillage est proposée afin d'éviter le problème de convergence qui vient de la grand contrainte cisaillement. Pour cela, le comportement au rayage est étudié par le changement de l'angle d'attaque, du coefficient de frottement local entre le matériau et l'indenteur. Ces influences sont valorisés par l'évolution des forces rayures, par la morphologie de l'échantillon, et ils montrent le mécanisme de changement des modes de rayage : du labourage à l'usinage avec la formation des copeaux. Les essais sont réalisés à l'aide de l'équipement du LARMAUR : Un nano-triboindenteur de type Hysitron Ti-950. La comparaison des résultats simulés et expérimentaux nous permettre d'évaluer la loi comportement utilisé et d'estimer la valeur de coefficient de frottement entre le matériau et l'indenteur. / This thesis contributes to modeling of the elasto-plastic behavior in scratch test of a Zr55Cu30Al10Ni5 Bulk Metallic Glasses (BMG) by the finite element method and by experimental testing. The Drucker-Prager criterion is used and dedicated re-meshing method is proposed in order to solve the numerical problems classically encountered when modeling such a test and this with a controlled element population. The influence of friction coefficient as well as the angle of attack are investigated to understand the occurrence of two deformation mechanisms : plowing and cutting. The test is realized by using the LARMAUR's equipment : nano triboindenter Hysitron Ti-950. The result of experimental and simulation are confronted the finite element simulations.
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Trafikbelastade gårdsbjälklag : En undersökning av beräkningsmetoders lämplighet och möjliga förenklingar i projekteringsprocessenHärd, Johan, Skoglund, Mårten January 2019 (has links)
As a structural designer, you are sometimes required to design structures carrying traffic loads, but which are not, for example, bridges or parking garages. In practice, this usually applies to drivable floor layers and culverts under roads. When designing structures such as bridges and parking garages, there are clear standards and regulations to follow. These types of guidelines are not as comprehensive when it comes specifically to dimensioning traffic-load-bearing constructions in connection with building construction. Frequently, an evenly distributed load of 20 kN/m2 is used. The purpose of this work is to investigate which regulations house construction designers should relate to when designing structures that carry traffic loads which are not bridges or parking garages. The work also includes an investigation of how suitable different calculation methods are for different types of load cases. The goal is to make recommendations that can streamline the work for construction designers. The material for this work has been obtained through three different methods. In order to gain an understanding of the subject and the current state of knowledge in the field, a literature study has been made. The main part of the work has included qualitative interviews with people who have good experience and knowledge in the field, as well as practical modeling and calculation of load cases. The focus has been on investigating which transverse forces occur for some specific load cases. The study also includes the effect of the fill layer’s thickness on the load spread. For larger floor spans, it is confirmed that an evenly distributed load of 20 kN/m2 is a bit heaped. To dimension after this covers most of the load cases that may occur on a floor layer or similar construction. In some cases, this value could be halved without problem. It also turns out that the shorter the span of the floor, the more the evenly distributed load differs between the different fill layer thicknesses. / Som husbyggnadskonstruktör får man ibland dimensionera konstruktioner som bär trafiklast, men som inte är exempelvis broar eller parkeringsgarage. I praktiken gäller det oftast körbara gårdsbjälklag och kulvertar under vägar. Gårdsbjälklag är ett något diffust begrepp. Vanligen innebär ett gårdsbjälklag ett bjälklag som skiljer insidan av en byggnad från någon typ av innergård. Normalt byggs dessa konstruktioner ovanpå parkeringsgarage eller källarvåningar. Ofta bär gårdsbjälklaget på de massor av material som planteringar, gräsmattor, vägar och gångar innebär. Gårdsbjälklag bär alltså i praktiken ofta på ett tätskikt, isoleringslager, samt diverse överbyggnader. Överbyggnaden kan bestå av jord, stenmaterial eller liknande massor. Dessa gårdsbjälklag kan även vara föremål för trafiklaster. Vanligtvis handlar det om uppställningsplatser för utryckningsfordon, men det finns också gårdsbjälklag där fraktfordon, servicefordon eller personbilar kan köra. Ofta trafikeras gårdsbjälklag även av fordon under byggskedet. Det kan exempelvis vara grävmaskiner, traktorer, lastbilar eller mobila kranar. Vid dimensionering av konstruktioner som broar och parkeringsgarage finns tydliga normer och regelverk att följa. Dessa typer av riktlinjer är inte lika omfattande när det specifikt gäller dimensionering av trafikbelastade konstruktioner i samband med husbyggnad. Ofta används en vedertagen utbredd last på 20 kN/m2. Syftet med detta arbete är att undersöka vilka regelverk husbyggnadskonstruktörer ska förhålla sig till vid dimensionering av konstruktioner som bär trafiklast men som inte är broar eller parkeringsgarage. Arbetet innefattar även en granskning av hur lämpliga olika beräkningsmetoder är för olika typer av lastfall. Målet är att ta fram rekommendationer som kan effektivisera arbetet för konstruktörer inom husbyggnad. Materialet för detta arbete har inhämtats genom tre skilda metoder. För att få en förståelse för ämnet och det aktuella kunskapsläget inom området har en litteraturstudie gjorts. Huvuddelen av arbetet har innefattat dels kvalitativa intervjuer med personer som har god erfarenhet och kunskap inom området, dels praktisk modellering och beräkning av lastfall. Fokus har legat på att undersöka vilka tvärkrafter som uppstår för några specifika lastfall. Undersökningen innefattar även vilken inverkan överbyggnader av olika tjocklek har på lastspridningen. De beräkningsprogram som har använts under arbetet är i synnerhet Strusoft FEM-Design. Även Strusoft Frame Analysis och PTC Mathcad Prime har nyttjats. Vid intervjuer med erfarna husbyggnadskonstruktörer framgick bland annat att dimensioneringsprocessen i de flesta fall är relativt simpel, men att vissa svårigheter kan uppstå, samt att en effektivisering av dimensioneringsprocessen för gårdsbjälklag är möjlig. Båda respondenterna nämnde att många konstruktioner troligen överdimensioneras till följd av användandet av gamla riktlinjer. Hur pass erfaren konstruktören är kan också spela in. Vidare kan det vid beräkning av laster på gårdsbjälklag vara både fördelaktigt och nödvändigt att räkna på lastspridningen i överbyggnadsmaterialet. En utförligare undersökning kring vilka laster man som konstruktör faktiskt bör räkna med för olika lastfall skulle därmed vara av intresse. Enligt en respondent saknas även en tydlig gränsdragning för i vilka fall EKS respektive specifika laster bör användas vid dimensionering. Resultatet från beräkningarna visar att stora utbredda laster uppkommer när spännvidderna blir mindre. Detta blir viktigt att beakta vid dimensionering av exempelvis kulvertar, där punktlasterna för de specifika lastfallen måste tas hänsyn till, givet att överbyggnaden inte är väldigt tilltagen. För större bjälklag bekräftas att en dimensionerande, jämnt utbredd last på 20 kN/m2 är väl tilltagen. Att dimensionera efter detta täcker de absolut flesta lastfallen som kan tänkas förekomma på ett gårdsbjälklag eller liknande konstruktion. I en del fall skulle detta värde kunna halveras utan att problem skulle uppstå. Det visar sig även att ju kortare bjälklagets spännvidd är, desto mer skiljer sig den motsvarande utbredda lasten mellan de olika överbyggnadstjocklekarna.
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DIMENSIONERING AV KONSTRUKTIONER I ROBOT STRUCTURAL ANALYSIS 2019 : Skillnader och likheter med FEM-DesignLindman, Joel, Westerlund, Lina January 2019 (has links)
The basis of this thesis was that Kåver & Mellin Uppsala wanted todetermine if they should train their employees in the software RobotStructural Analysis. The company had licenses for the program that theydid not use due to lack of experience. The purpose of the project wastherefore to examine how Robot is used for designing structures and tocompare its usefulness to its competitor FEM-Design. The comparison ofusefulness was made by designing an identical structure in bothprograms. The focus of the study was to compare three main areas,workflow, areas of use and calculation results. This was made for themost common construction elements that were limited to concrete slabs,concrete walls, steel columns and steel beams.The study proved the programs to be similar. Designing steel profilesis more efficient in Robot. Another advantage of Robot is that there isan official online help page and a useful online forum, that FEM-Designlacks. One significant disadvantage of Robot is that the calculationsfor concrete are made with outdated national standards for Eurocode.The disadvantage was crucial and led to the conclusion that Kåver &Mellin Uppsala should wait for updated standards before using theprogram fully but they could start using Robot for load calculationsand steel design.
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Utveckling av ramverk för FAB – Fully Automatic Bagging : Ett produktutvecklingsprojekt / Framework development for FAB – Fully Automatic Bagging : A product development projectThorn, Johan January 2019 (has links)
Denna rapport behandlar ett examensarbete som gjorts på Goodtech Solutions AB i Karlstad. Examensarbetet är ett avslut på Högskoleingenjörsprogrammet i maskinteknik vid Karlstads universitet. Målet med projektet var att utveckla en ny typ av lösning för ett ramverk till en bulkhanteringslinje för att effektivisera tillverkningen och på så sätt öka lönsamheten på produkten. Produktutvecklingsprocessen låg till grund som metod för projektet och genom att steg för steg följa de olika faserna kunde en rad koncept tas fram. Ur dessa kunde ett slutgiltigt konceptval göras och därefter skapa en CAD-modell med hållfasthetsberäkningar som underlag. Den nya konstruktionen löser de tidigare problemen med en robust ram och förenklad konstruktion samt fullständig tillgång till underhållspunkter. Ramverket är konstruerat med hänsyn till innermåtten på en ISO-container och är även dimensionerad för både svartstål och rostfritt vilket har resulterat i en ökad flexibilitet hos produkten. / This report deals with a degree project done at Goodtech Solutions AB in Karlstad. The degree project is a conclusion to the Bachelor of Science program in mechanical engineering at Karlstad University. The aim of the project was to develop a new type of solution for a framework for a bulk handling line to make production more efficient and thus increase the profitability of the product. The product development process was based on the method for the project and by following the different phases step-by-step, a number of concepts could be developed. From these, a final concept selection could be made and then create a CAD model with strength calculations as a basis. The new design solves the previous problems with a robust frame and simplified design and complete access to maintenance points. The framework is designed with regard to the inner dimensions of an ISO container and is also dimensioned for both black steel and stainless steel, which has resulted in an increased flexibility of the product.
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DESIGN AND CONSTRUCTION OF A STEPLESS HEIGHT ADJUSTER FOR AN ASKO DISHWASHERNyman, Jonas, Krivokuca, Vladimir January 2019 (has links)
The standard for standing household dishwashers to date includes some means of adjusting the height of the upper basket in order to facilitate a more efficient loading of dishware. Ordinarily this is done by lifting the basket and locking it in a few positions. A more efficient and satisfactory method of handling the elevation that instils a premium sensation was to be developed. A design process was initiated and using CAD, a 3D model with associated drawings was created. A FEM analysis was conducted on the most vital components and a subsequent prototype was built. Preliminary results indicated flaws in the construction, however developing solutions appeared promising. The FEA concluded that the key components were sufficiently dimensioned for the tasks given. In the end, the project requirements were fulfilled although with set conditions modified, and without an end user trial.
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Evaluation of Different Concepts for Pressed and Sintered Connecting RodsRehn, Mattias January 2019 (has links)
Connecting rod are found in most combustion engines and transmits thrust from the piston to the crankshaft. The connecting rod needs to withstand forces from the piston and inertia forces which results in axial tension, compression stresses and bending. Today the most common manufacturing techniques in automotive industry are drop-forging, die-casting and the Powder Metallurgy technique used is powder-forging. In this Master Thesis different connecting rod designs for a single press PM manufacturing process were created and evaluated as a part of Höganäs AB's Total Powder Metal Car project, TPMC. This paper will serve as a basis for future connecting rod projects at Höganäs AB when choosing a suitable connecting rod design. The main objective of this Master Thesis is to evaluate different designs in regards to the following: Buckling strength Fatigue life Manufacturing rating The study shows that there is evidence that a single pressed connecting rod is possible. No absolute answer of which design is the best is given in this paper since in depends on different parameters and application. For each parameter examined there are results presented and arguments for and against each design which can aid designers in future work. Suggestions of improvement on both the method and on the designs are presented in respect to the results. The improvements may potentially increase the fatigue life, buckling strength and improve manufacturability.
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Säkerhet- och kvalitetsanalys av rulltrappor : En undersökning av trappsteg med avseende på hållfasthetJohansson, Filip January 2019 (has links)
No description available.
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Transfer Mold DesignWang, Xiaoyan, Patel, Parthkumar January 2019 (has links)
The following report conducted with the collaboration with the University of Halmstad and Halmstad Gummi Fabric (HGF) rubber company which is in Halmstad. The focus on the project is to reduce the cost of the transfer mold material, increase efficiency of production, save energy and redesign the transfer mold. The methodology used in this project is based on the Quality Functional Deployment (QFD) which is widely appreciated globally in the product development, and other product development and mold design methods, FEM analysis are applied to achieve the goals. The implementation of this methods is efficient and beneficial to reduce the material cost and redesign the transfer mold without compromising the initial quality of the product. This thesis resulted in, for the transfer molding plates we recommended the proper material for the plates and the insulation parts. And we redesign the transfer mold plates and optimized the design for reducing the cost. We did FEM analysis for optimization purpose, and the benefits to optimizing this is to reduce the material cost, machining cost and labour cost. As well as, we add the insulation plates in the design so that the transfer molding plates works efficiently with the reducing the energy wastes.
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