La pénétration des ions chlorure est la principale cause de la dégradation des structures en béton, par corrosion des armatures, entraînant un impact sévère sur leur durabilité et leur durée de vie. La pénétration de ces agents agressifs pourrait être favorisée davantage par la présence de fissures. Dans cet thèse, nous avons utilisé la méthode des éléments finis (EF) pour résoudre l'équation de la loi de Fick couplée à la capacité de fixation d’ions chlorure afin de modéliser la diffusion des ions chlorure à l’échelle mésoscopique. Dans un premier temps, nous avons considéré une représentation 3D d’un matériau, sain, hétérogène biphasé (comme le béton) ou les inclusions (granulats) sont noyées dans une matrice de mortier. Le problème des interfaces (inclusion/matrice) a été résolu en utilisant la méthode E-FEM (Embedded Finit Element Method). Au niveau de ces interfaces, nous avons introduit une discontinuité faible du champ de concentration de chlorures. Une approche d’homogénéisation par moyennes spatiales se basant sur les travaux de Pouya est également utilisée pour prédire les tenseurs de diffusivité macroscopiques des matériaux biphasiques. La comparaison avec l'équation de Maxwell et des résultats expérimentaux a été réalisée pour montrer la précision de l’approche numérique proposée. Dans un second temps, l’approche méso-macro est représentée pour introduire un modèle numérique capable de fournir des informations macroscopiques (tenseur de diffusion moyen) intégrant le niveau d’ouverture de fissure, le chemin de fissuration et l’hétérogénéité des matériaux quasi fragiles tels que les matériaux cimentaires (béton, mortier, ….). Dans ce cas, des points clés du processus de fissuration comme l’évolution d’une fissuration répartie vers une fissuration localisée (macro-fissure(s)), la tortuosité de la fissure et son anisotropie sont intégrées naturellement dans la diffusivité macroscopique. En fin, le tenseur défini est ensuite utilisé afin d'estimer la durée de vie des structures en béton, y compris l'effet de l'endommagement et de la mésostructure interne. / The penetration of chloride ions has an essential responsibility in the degradation of concrete structures caused by reinforcement corrosion leading to a severe impact on the durability and service life of concrete structures. The problem becomes more critical with the existence of cracking which accelerate the penetration of chloride ions into concrete cover. In this work, the FE formulation for the numerical modelling of chloride ions diffusion accounting for chloride binding capacity in mesoscale concrete is introduced. The mesostructure is based on a twophase 3D representation of heterogeneous materials, such as concrete, where stiff aggregates are embedded into a mortar matrix. For this purpose, we turn to the Embedded Finite Element Method (E-FEM). This is performed by introducing a weak discontinuity in the chloride concentration field for finite elements where the physical interface is present. Numerical spatial homogenization experiments based on Pouya’s works are also performed on 3D mesostructures to compute macroscopic diffusivity tensors accounting for two-phase material. Comparison with Maxwell's equation and experimental results are carried out to show the accuracy of the proposed numerical approach. Finally, the meso-macro approach is presented to introduce a numerical model capable of providing macroscopic information (mean diffusivity tensor) integrating the level of crack opening, crack path and heterogeneity of materials in quasi-brittle concrete. The mesoscale coupling with the mass transport part is based on Fick’s Law with a modified diffusion coefficient taking into account crack opening and aggregates. The macroscopic diffusivity tensor integrates more complex features such as the cracking evolution process, tortuosity of the crack’s path, inducedanisotropy and presence of aggregates. The defined tensor is used afterwards in order to estimate the service-life of concrete structures, including the effect of the cracking and the internal mesostructure.

Disc brakes, which are essential safety components in automobiles, are profoundly affected by conditions at the pad-to-rotor interface. In this research, 3D modeling of the brake system was conducted using CATIA, supplying a comprehensive visual representation crucial for our analysis. The finite element analysis (FEA) was performed with ANSYS Workbench, allowing for an in-depth examination of wear mechanisms and their associated temperature history. To closely mirror real-world scenarios, tests were conducted using the Bruker UMT system equipped with a heating chamber, adhering to the SAE J2522 standard. Despite the robust methodologies employed, achieving the desired wear performance proved challenging. A significant inconsistency was observed between experimental and the simulation results. This disparity underscores potential inadequacies in the current simulation models and highlights the need for a more precise inclusion of material properties. This study recommends refining these models, addressing their inherent limitations, and optimizing testing parameters. A pivotal suggestion is incorporating enhanced material properties into the 3D models to improve accuracy. With these enhancements, the aim is to bridge the gap between simulated and real-world brake wear performances, thereby promoting more reliable braking systems.

Sammanfattning Att testa sina prototyper är en viktig del av all produktutveckling. På Roxtec i Karlskrona sker kontinuerlig vidareutveckling av företagets produkter. För att kontrollera nya idéer tillverkas prototyper vilka testas i tryckkärl byggda för ändamålet. Personalen anser att kärlen inte uppfyller deras önskemål på en bra testutrustning.  Genom intervjuer med berörda sammanställs de behov som finns kring tryckkärlet. Den största bristen är ställtiderna mellan varje test, i övrigt uppfyller kärlet de behov som finns.  Testerna sker genom att en platta med den produkt som skall testas monteras med flera skruvar på ett tryckkärl. Kärlet fylls med vatten och trycksätts till önskat tryck. Den största andelen av tiden går åt till montering och demontering av testplattan och att fylla och tömma kärlet på vatten.    Det befintliga kärlet vidareutvecklas för att minska tiden mellan varje test. En simulerad modell av kärlet visar de bultar som fäster test plåten inte kan minska i antal men de behöver inte förspännas med samma kraft som i dagsläget. Vidare visas hur ställtiderna kan minskas genom att kärlet tippas för att inte  vattnet skall behöva tömmas vid varje nytt test.  Dagens tryckkärl uppfyller större delen av personalens behov. För att minska ställtiderna bör trycksättningsvätskan återanvändas efter varje test och inspänningsanordningen förenklas. Att minska antalet skruvar är inte lämpligt med dagens konstruktion. Monteringen förenklas något genom att verktyg inte behöver användas vid monteringen.

The structural integrity of a welded structure depends mainly on the performance of the welded joints. Due to the welding process, the mechanical properties of the structure change and different regions are created in the weldment. The mechanical properties of welded joints change significantly around the heat affected zone (HAZ). So to predict stress distribution around the weld, these changes should be considered in the finite element model (FEM) of the welded structure. In this research, the changes of mechanical properties around the welded joint were experimentally tested and used to develop a FEM model of a welded joint which can predict the stress behavior around the weld. First, an experimental analysis was carried out on an ASTM standard arc welded joint of stainless steel specimen to observe the microstructural change in the HAZ. This enables to find out the HAZ width using an optical microscope. Moreover, a tensile testing was performed to investigate the change of Young’s modulus of the HAZ compared to the base metal (BM). Another experimental analysis was also performed on a real arc welded structure of the same material to observe its’ strain distribution around the HAZ. The HAZ width and Young’s modulus obtained from the experimental testing were then applied to generate the FEM model of an ASTM standard arc welded joint as well as a real arc welded structure of stainless steel. The finite element analysis (FEA) results of stress distribution around the weld joint in both cases show a good agreement with the experimental results. Therefore, the developed material property based FEM model can predict the stress behavior of similar type of structures with the same welding process on the same material studied in this research. / February 2017

<p>Syftet med detta examensarbete är att undersöka och jämföra två olika beräkningsmetoder när det kommer till beräkningar av väggskivor. Den ena beräkningsmetoden baserar sig på traditionella handberäkningar där anvisningarna i BBK 04 (Boverket 2004) och Betonghandbok Konstruktion (Lorentsen, Mogens, Cederwall, Krister & Östlund, Lars (red.) (1990)) följs. Den andra metoden baserar sig på finita elementmetoden, och utförs med hjälp av programmet Strusoft FEM-Design Wall. Med Finita elementmetoden delas konstruktionen upp i flera små delar, så kallade finita element, som sedan beräknas var för sig, och sedan sätts alla delarna ihop till ett resultat för hela konstruktionen. Två olika väggskivor beräknades, en solid väggskiva samt en väggskiva med ett dörrhål i.</p><p> </p><p>Vid jämförelsen på den solida väggskivan visade sig resultaten stämma väl överens med varandra. Ungefär lika stor erforderlig armeringsarea erhölls med bägge beräkningsmetoderna. Dock så gav det FEM-baserade programmet en någon större armeringsmängd mätt i kg armering per kubik betong.</p><p>Vid jämförelsen av väggskiva 2, vilken hade ett dörrhål intill ena stödet, visade det sig att de olika beräkningsmodellerna betraktade konstruktionen på olika sätt, så där gick inte den erforderliga armeringsarean att jämföra på samma sätt. Här jämfördes istället de olika armeringsutföranden som erhölls.</p><p> </p><p>Att jämföra de olika beräkningsmetoderna direkt mot varandra och säga vilket som gav det bättre resultatet visade sig vara mycket svårt, då det är helt olika metoder. Generellt kan det sägas att de olika metoderna passar bra vid olika tillfällen.</p> / <p>The intent of this essay is to perform a comparison between two different methods to calculate wall-beams. The first method is based on manual calculations performed according to the Swedish building regulations BBK 04 (Boverket 2004) and  Betonghandbok Konstruktion (Lorentsen, Mogens, Cederwall, Krister & Östlund, Lars (red.) (1990)). The second method is based on the finite element method (FEM), and is performed using the computer program Strusoft FEM-Design Wall. With the finite element method the construction is divided into smaller volumes, referred to as finite elements, which are calculated separately and then joined together to get a calculated result for the whole construction.</p><p>The calculations were performed on two different wall-beams, one solid, and one containing a door opening.</p><p> </p><p>The comparison on the solid wall-beam showed that the two different methods resulted in about the same result. Although the calculation of program based on FEM resulted in a little larger amount of rebar measured in kg rebar per cubic meter concrete.</p><p>On the comparison of the second wall-beam, which contained a door opening near one of the supports, proved that the two different methods looked upon the construction different ways. Because of this, no comparison of the required amount of rebar could be performed. Instead the different ways of the positioning of rebar were investigated.</p><p> </p><p>To make the comparison of the two different methods proved to be very difficult, due to the fact that these are very different. Generally speaking it could be said that the two different methods are suitable in different situations.</p>

<p>This thesis has been made in cooperation with the forestry machinery producerEco-Log in Söderhamn. The focus of the thesis has been to find a cheaper wayto open the large engine hood of the company’s harvesters. The goal was tofind a solution that could increase the value for the customers by being saferand simpler to use, or, at the least, keep these values at an equal level comparedto the previous solution.In order to make it possible to CE-mark the new solution, it was importantMachinery Directive that came into effect from the beginning of 2010.To begin with, a specification of requirements was set up. Thereafter, anumber of different basic concepts was retrieved and evaluated. The chosenconcept was to use electro-mechanical actuators for the opening of the largeengine hood. A market research was made, where a number of differentactuators were chosen. Thereafter, a program that found possible placementsfor them was designed. Some of the alternatives were test assembled in theCAD-model of the machine, which gave information for a meeting with theEco-Log engineering team, where one final concept was to be chosen.The chosen concept was based on using an actuator from the manufacturerLinak with the stroke of 400 mm that was to be placed in a horizontal positiondirectly under the hood. To ensure that the hinges would be able to resist thenew pressure, a new hinge concept was developed. All parts of the finishedoverall concept were stress tested with FEM-analysis to detect any problems.The mounting brackets on the tank bow and in the hood were created in 8mm sheet metal. To endure the surface pressure in the mounting hole on thebracket, the mounting plates will be manufactured in steel with a yield point of500-650 MPa.The actuator is manoeuvred by a spring centre rocker switch. To be able toaccess emergency manual operation the actuator will be mounted in a 30degree angle.To sum up, the final solution was cheaper, safer and easier to assemble.</p>

Syftet med detta examensarbete är att undersöka och jämföra två olika beräkningsmetoder när det kommer till beräkningar av väggskivor. Den ena beräkningsmetoden baserar sig på traditionella handberäkningar där anvisningarna i BBK 04 (Boverket 2004) och Betonghandbok Konstruktion (Lorentsen, Mogens, Cederwall, Krister &amp; Östlund, Lars (red.) (1990)) följs. Den andra metoden baserar sig på finita elementmetoden, och utförs med hjälp av programmet Strusoft FEM-Design Wall. Med Finita elementmetoden delas konstruktionen upp i flera små delar, så kallade finita element, som sedan beräknas var för sig, och sedan sätts alla delarna ihop till ett resultat för hela konstruktionen. Två olika väggskivor beräknades, en solid väggskiva samt en väggskiva med ett dörrhål i.   Vid jämförelsen på den solida väggskivan visade sig resultaten stämma väl överens med varandra. Ungefär lika stor erforderlig armeringsarea erhölls med bägge beräkningsmetoderna. Dock så gav det FEM-baserade programmet en någon större armeringsmängd mätt i kg armering per kubik betong. Vid jämförelsen av väggskiva 2, vilken hade ett dörrhål intill ena stödet, visade det sig att de olika beräkningsmodellerna betraktade konstruktionen på olika sätt, så där gick inte den erforderliga armeringsarean att jämföra på samma sätt. Här jämfördes istället de olika armeringsutföranden som erhölls.   Att jämföra de olika beräkningsmetoderna direkt mot varandra och säga vilket som gav det bättre resultatet visade sig vara mycket svårt, då det är helt olika metoder. Generellt kan det sägas att de olika metoderna passar bra vid olika tillfällen. / The intent of this essay is to perform a comparison between two different methods to calculate wall-beams. The first method is based on manual calculations performed according to the Swedish building regulations BBK 04 (Boverket 2004) and  Betonghandbok Konstruktion (Lorentsen, Mogens, Cederwall, Krister &amp; Östlund, Lars (red.) (1990)). The second method is based on the finite element method (FEM), and is performed using the computer program Strusoft FEM-Design Wall. With the finite element method the construction is divided into smaller volumes, referred to as finite elements, which are calculated separately and then joined together to get a calculated result for the whole construction. The calculations were performed on two different wall-beams, one solid, and one containing a door opening.   The comparison on the solid wall-beam showed that the two different methods resulted in about the same result. Although the calculation of program based on FEM resulted in a little larger amount of rebar measured in kg rebar per cubic meter concrete. On the comparison of the second wall-beam, which contained a door opening near one of the supports, proved that the two different methods looked upon the construction different ways. Because of this, no comparison of the required amount of rebar could be performed. Instead the different ways of the positioning of rebar were investigated.   To make the comparison of the two different methods proved to be very difficult, due to the fact that these are very different. Generally speaking it could be said that the two different methods are suitable in different situations.

This thesis has been made in cooperation with the forestry machinery producerEco-Log in Söderhamn. The focus of the thesis has been to find a cheaper wayto open the large engine hood of the company’s harvesters. The goal was tofind a solution that could increase the value for the customers by being saferand simpler to use, or, at the least, keep these values at an equal level comparedto the previous solution.In order to make it possible to CE-mark the new solution, it was importantMachinery Directive that came into effect from the beginning of 2010.To begin with, a specification of requirements was set up. Thereafter, anumber of different basic concepts was retrieved and evaluated. The chosenconcept was to use electro-mechanical actuators for the opening of the largeengine hood. A market research was made, where a number of differentactuators were chosen. Thereafter, a program that found possible placementsfor them was designed. Some of the alternatives were test assembled in theCAD-model of the machine, which gave information for a meeting with theEco-Log engineering team, where one final concept was to be chosen.The chosen concept was based on using an actuator from the manufacturerLinak with the stroke of 400 mm that was to be placed in a horizontal positiondirectly under the hood. To ensure that the hinges would be able to resist thenew pressure, a new hinge concept was developed. All parts of the finishedoverall concept were stress tested with FEM-analysis to detect any problems.The mounting brackets on the tank bow and in the hood were created in 8mm sheet metal. To endure the surface pressure in the mounting hole on thebracket, the mounting plates will be manufactured in steel with a yield point of500-650 MPa.The actuator is manoeuvred by a spring centre rocker switch. To be able toaccess emergency manual operation the actuator will be mounted in a 30degree angle.To sum up, the final solution was cheaper, safer and easier to assemble.

The degree project was made forZetterbergs Industri AB. The company is market leading in Europe in the heavyvehicle industry, designing and building body systems for trucks.In their line of products is the hook lift called Livab, a flexible and uniqueproduct. The hook lift is often demanded by customers because its special ability tobe able to operate in situations with low roof clearance. The main operation principleof the hook lift can be described as a truck stand, laid down.There are two main versions of the hook lift Livab, AL 26 and AL 32. These are ofdifferent load capacity, 17 and 25 metric tons of gross weight respectively. The aim ofthis project was to try to find a concept that could replace the AL 26 and in turns ofload capacity qualifies somewhere in between the two existing versions. The conceptshould ideally also have lower weight and a lower build up height than the existinghook lift because of competitive advantage.The results was a FEM based analysis of different concepts to change the crosssections of the beams that make up the construction. These concepts where thencompared to each other. Also, different concepts of making the chassis mountedframe of the hook lift lighter by trying different reinforcement crosses, were analyzedin the same manner.The selected concepts was in the end, for the inner stand: "kompakt profiler insida",for the outer stand "kompakt" and for the reinforcement cross "original".

Remote field eddy current (RFEC) testing is an eddy current non-destructive test method that has become widely used for the examination of carbon steel tubes, such as those found in heat exchangers and boilers. RFEC testing relies on the use of very low intensity electromagnetic fields on the exciting probe. The defect detection is carried out considering the phase difference between the exciting and pickup signals. However, various testing effects were produced because the affection of different electromagnetic characteristics of tubes and types of defects The purpose of this study is to analyze the influential factors of RFEC testing accuracy by means of the finite element method (FEM). In order to investigate the numerical simulation, the researcher used the finite element software package FEMLAB to create an electromagnetic model of RFEC testing. Then he applied the mathematics software package MATLAB to plot the voltage plane diagram and defect-phase difference diagram. After the comparison of the simulation with experiments, the researcher confirmed the reliability of electromagnetic simulation. As a result, this study provides the variations in RFEC testing result diagrams for the influential factors. Over all, this study has successfully established an FEM RFEC electromagnetic model. After the FEM simulation, this method can provide many comparable data for experimenter. This study may remedy the different types of defects and reduce assessing error. Therefore, the accuracy and reliability of testing of RFEC can be accessed.