The purpose of this thesis is to understand dynamic behaviors of carbon fiber composite golf shaft and the influence of different carbon fiber shaft flexes on club heads. To achieve the purpose, the researcher used the finite element method (FEM) software LS-DYNA and ANSYS to analyze the dynamic behaviors of carbon fiber composite golf shaft. He also applied three rigid bodies and two revote joint in a swing mode to simulate swing motion. In the same driving moment, the comparison provides golfer with a reference for selecting suitable carbon fiber composite golf shaft. It also offers other researchers an FEM model to do further analysis of dynamic behaviors of golf heads with the carbon fiber composite shaft.

With the popularity of golfing, the marketing of golf clubs has been promoted in recent years. The purpose of this study is to investigate the sound effects of golf impact on different shapes and thicknesses of striking face of the golf club using the finite element method. The researcher found that the vibration model and the resonance frequency of golf club heads. In addition, the researcher used vibration modal analysis to generalize the golf head modes with the distribution of the sound pressure. He also used acoustic transient analysis to check the sound pressure level. Finally, the correlations among the sound pressure, sound pressure level and sound frequency of the golf club head impacts were administered. After all, the study findings provides golf head designers and producers with a reference for designing, revising and producing comfortable and qualified impact sounds of golf club heads.

The plastic deformation of stent is investigated in this study and the effect of atherosclerotic artery on the stent deformation is studied. The relationship between different stent structure parameters; i.e., stent thickness, length, slot length ration and final deformation are also discussed. The elastic-plastic finite element models is employed in the deformation and residual stress analysis. The materials of balloon, stent and artery were assumed to be linear elastic, elasto-plastic and nolinear-elastic Odgen model, respectively. A typical Palmaz type stent is analyzed. The deformation and stress distributions of the stent are simulated with the inflation and the deflation of the angioplasty balloon. Results indicate that the considering of the atherosclerotic artery may affect the calculated stent deformation and stress distributions significantly.

The thermal stresses, residual stresses distributions in a vertical cavity surface emitting laser (VCSEL) are investigated in this thesis. The post-weld shifts of the laser light sources in the VCSEL under the re-flow, temperature cycling test and high temperature aging test have also been simulated and studied. The creeping effects of the 63Sn/37Pb solder on the stresses distributions and post-weld shifts are compared and discussed. The finite element package MARC is used for the stresses and deformation simulations of a VCSEL under different load cases. The heat transfer, the non-linear couple elastic-plastic increment and the creep models are employed in the numerical simulations. The temperature dependent material properties of the 63Sn/37Pb and 96.5Sn/3.5Ag solder are used for the temperature cycling and aging test. The effect of the circle and square solder pad designs on the stresses distributions in a VCSEL is also studied in this thesis. Numerical results indicate that the residual stresses introduced in the solidification is significant in stress and post-weld analyses of a VCSEL.

This report was produced at the request of ABB Robotics and the work was conducted at their facilities in Västerås, Sweden. In the development of industrial robots the structures are slimmed to increase the accuracy and speed. When conducting finite element analysis on the robots the accuracy of the component modelling and definitions of the boundary conditions becomes more important. One such component is the ball bearing which consist of several parts and has a nonlinear behavior where the balls are in contact with the rings. The task given was to develop new methods to model roller bearings in Siemens finite element modelling software NX Nastran. Then conduct a strain measurement, to compare the methods to real experimental values. The goal with the report is to find one or more methods to model roller bearings, with accurate results, that can beused in their development work. The report was conducted by first doing a study on bearings and finite element modeling, and learning to use the software NX Nastran. Then the development of the methods were done by generating ideas for bearing models and testing them on simple structures. Nine methods was produced and a tenth, the method used to model bearings today, was used as a reference. The methods was used to build bearing models in a finite element model of a six axis robot wrist. Simulations were done on the models with different load cases and the results were compared to a strain measurement of the wrists real counterpart. Only six of the models were analyzed in the result, since four of the models returned results that were deemed unusable. When compiling the result data no model was found to accurately recreate the stresses in every load case. Three methods, that allow deformation, performed similarly. One of them is suggested to be used as modelling method in the future. Worst of the methods, according to the results compiled, was found to be the method used today. It fails to describe local stresses around the bearing. For continued work it is suggested that linear contact elements is studied further. Four out of five models constructed with linear contact elements failed to return satisfactory results.

This degree project was conducted in collaboration with Gremo AB located in Ätran. The aim of the project was to develop a solution to secure quality and to help assembling the locknut holding the vertical hinge on the harvesters and foresters from Gremo. At this time the nut is assembled manually by the aid of an overhead crane. The nut is tightened differently from time to time, and there was no specified torque to which it is tightened. Another present problem was the locking washer which sometimes gets damaged during assembly, when this happens the procedure has to be started over from the beginning. The current assembly procedure is very time consuming and lengthy for the employees. Our task was to design a machine that could tighten the nut to a specified torque with a margin of error of ± 3%. The assembly procedure will be held simple and the time required at a minimum. The project started by developing several principle solutions, the one solution that best matched our specifications were developed to a primary solution. Today we have started manufacturing and assembling our prototype. Our goal is that the equipment will be taken into use by Gremo.

In motorsports competition, safety reasons require that the vehicle is equipped with some form of protective roll cage. The roll cage should withstand the forces involved in a collision to protect the driver and the co-driver from the vehicle body deformation. The roll cage also works to protect the vehicle from excessive deformations to more easily make any repairs afterwards. For the roll cage to be certified and approved for motorsports competition, it requires that the cage is built after one of the recommended options. One of those options is to design the roll cage like a cross-construction at the driver and co-driver doors. This requires welding in the middle of the construction at the doorway, which can lead to embrittlement in this area. In case of a collision this can be a risk. A new structural design is tested and compared to the recommended solution. Finite element-simulations show that high stresses occur around the weld areas when the structure is exposed to forces. It’s also found that the new design solution can have negative effect on the surrounding roll cage, why an alternative solution is presented. This solution exhibits the lowest stresses and keeps the stresses in the surrounding roll cage on acceptable levels, why this construction is recommended. / Inom motorsporttävling krävs det vanligtvis av säkerhetsskäl att fordonet är utrustad med någon form av skyddsbur. Skyddsburens uppgift är att stå emot de krafter som uppstår vid kollision och på sätt skydda föraren och co-driver från fordonskarossens deformation. Delvis är också burens uppgift att skydda fordonet från alltför stora deformationer för att enklare kunna göra eventuella reparationer i efterhand. För att skyddsburen ska bli certifierad och godkänd för motorsporttävling krävs det att buren utformas enligt en viss standard. Ett av de alternativ som rekommenderas är en kryss-konstruktion vid förar- och passagerardörren. Detta kräver en svetsning mitt i dörröppningen vilket kan medföra risker vid en kollision eftersom materialet kan försprödas i svetsområdet. En ny konstruktionsutformning testas och jämförs med den rekommenderade lösningen. Finita element-simuleringar visar att det uppstår höga spänningar vid svetsområdet när konstruktionen utsätts för lastpåkänningar. Det visar sig också att den nya konstruktionslösning kan medföra negativa effekter på den omgivande burkonstruktionen, varför ytterligare en alternativ lösning presenteras. Denna lösning uppvisar lägst spänningar samt behåller spänningarna i omgivande skyddsbur på godkända nivåer, varför denna konstruktion rekommenderas.

Detta examensarbete har utförts av två studenter som läser byggingenjörsprogrammet på Örebro universitet. Arbetet har titeln ”En jämförelse mellan handberäkningar och FEM-analys vid lastnedräkning” och handlar om de skillnader i lastfördelning man erhåller när man räknar på hur laster i en byggnad fördelar sig mellan de olika bärande elementen med de olika metoderna. FEM-analysen utfördes i datorprogrammet FEM-Design (StruSoft). Eftersom en lastnedräkning är ett grundläggande (men viktigt) steg i en konstruktörs design/dimensionerings-arbete så ville vi undersöka hur dessa görs och vilka verktyg ingenjörer har som kan hjälpa dem. Olika metoder att utföra detta kan komma att ge olika resultat. Vi jämförde de metoder som är vanligast, handberäkningar samt en FEM-analys med ett av de vanligare förekommande programmen som används av konstruktörer.Detta arbete har utförts i samarbete med företaget Integra Engineering AB, örebrokontoret. Integra har bidragit med 2D-ritningar till ett av deras projekt som denna grupp sedan gjorde en handberäknad lastnedräkning på samt modellering och FEM-analys med FEM-Design. Resultaten av de båda metoderna samanställdes sedan och analyserades för att få svar på de frågeställningar som ställdes.Som resultat förväntades skillnader, men för just detta projekt blev skillnaderna större än vad som väntades. Skillnaderna mellan totallasterna är acceptabla, men själva fördelningen mellan elementen blev större än förväntat. / This bachelors thesis has been carried out by two civil engineering students and has the title “A comparison between standard hand calculations and FEM-Analysis at load distribution analysis” and deals with the differences in load distribution that you can get between the different load-bearing elements (e.g walls and pillars). The FEM-analysis was performed in the program FEM-Design (by StruSoft). Since a load distribution analysis is a fundamental (yet important) step in an engineer’s design/dimensioning work. We wanted to research how the different methods work and what tools engineers have to aid them in these calculations. Different methods can yield different results. We chose to work with the two most common methods of analysis, a calculation done by hand (according to Eurocode) and a FEM-analysis that is used by structural engineers and is one of the most commonly used FEM-programs.This thesis has been carried out in cooperation with Integra Engineering AB, Örebro office. For this work, Integra has contributed with 2D-drawings of one of their projects as this group then performed a hand-calculated load distribution analysis aswell as modeling and FEM analysis of the FEM-Design software. The results of the two methods were then compiled and analyzed to answer the questions posed.As a result, differences were expected, but for this particular project the differences were larger than expected. The differences between the total loads are acceptable, but the actual distribution between all the elements became larger, when comparing the two results.

In der vorliegenden Arbeit wird die reproduzierbare Herstellung des Crimp eines Solarzellenverbinders (plastische Verformung zur Überbrückung des Höhenunterschiedes von Solarzellen) näher untersucht. Ausgehend von der theoretischen Betrachtung des Biegeprozesses und der parametrisierten Crimpform konnten Optimierungspotentiale der Crimpvorrichtung durch eine numerische Simulation mittels Finite-Elemente-Methode identifiziert werden. Eine Parameterstudie hat gezeigt, dass die Crimplänge den größten Einfluss auf die plastische Deformation des Solarzellenverbinders hat. Im Ergebnis dieser Studie ist außerdem ein Zusammenhang zwischen Vorrichtungs-, Material- und Crimpparametern entstanden, welcher zukünftig für die Betrachtung weiterer Chargen genutzt werden kann. Die optimierte Crimpvorrichtung wurde abschließend an Solarzellenverbindern mit und ohne Lot in verschiedenen Crimplängen getestet. Hierbei konnten die Ergebnisse aus den Simulationen bestätigt werden. Es kann festgehalten werden, dass durch eine systematische Anpassung des Verfahrweges und durch richtige Ausrichtung der Vorrichtung reproduzierbare Crimp erzeugt werden können.:1 Einleitung 2 Stand der Technik 2.1 Solarzellenverbinder 2.2 Biegehandpresse 2.3 Theorie der Blechbiegung 2.3.1 Der Biegevorgang 2.3.2 Arten von Biegevorrichtungen 2.3.3 Parameter des Biegevorgangs 2.3.4 Rückfederung der Biegezone 3 Beschreibung der Crimpformen 3.1 Darstellung der crimpformbeschreibenden Parameter 3.2 Berechnung der abhängigen Parameter 3.3 Konstruktiver Aufbau der Biegevorrichtung 3.4 Funktion der einzustellenden Parameter 4 Numerische Simulation des Formvorgangs 4.1 Voruntersuchungen 4.1.1 Darstellung der reduzierten Modelle 4.1.2 Materialdefinition 4.1.3 Untersuchung der Netzkonvergenz am SZV 4.1.4 Lagerung und aufgeprägte Verschiebung 4.1.5 Analyse der einzustellenden Parameter 4.1.6 Stiftdeformation 4.1.7 Biegeradius 4.1.8 Verfahrweg 4.1.9 Loteinfluss 4.2 Parameterstudie 4.2.1 Ergebnis der Antwortfläche 4.2.2 Antwortflächenbasierte Optimierung 4.2.3 Rückfederungswinkel 5 Darstellung des Optimierungspotentials der bestehenden Konstruktion 5.1 Präzisierung der Konstruktionsaufgabe 5.1.1 Anforderungsliste 5.1.2 Prüfung der Anforderungskonsistenz 5.2 Konstruktionsvarianten 5.2.1 Variante A 5.2.2 Variante B 5.2.3 Variante C 5.3 Bewertung und Auswahl 5.3.1 Ermittlung der Wichtungskoeffizienten 5.3.2 Vergleich der Konstruktionsvarianten 5.3.3 Auswahl der umzusetzenden Variante 5.4 Optimierte Konstruktion 5.5 Einstellungsoptimierte Konstruktion 6 Praktische Untersuchungen des Crimp 6.1 Versuchsaufbau 6.2 Versuchsdurchführung 6.3 Ergebnisdarstellung und -diskussion 6.3.1 Ergebnisvergleich innerhalb einer Versuchsreihe 6.3.2 Ergebnisvergleich zwischen zwei Versuchsreihen 6.3.3 Ergebnisvergleich zwischen Simulation und Praxis 6.4 Bewertung der Reproduzierbarkeit 7 Zusammenfassung 8 Ausblick

Waveguides are used to transmit electromagnetic signals.Their geometry is typically long and slender their particularshape can be used in the design of computational methods. Onlyspecial modes are transmitted and eigenvalue and eigenvectoranalysis becomes important. We develop a .nite-element code for solving theelectromagnetic .eld problem in closed waveguides .lled withvarious materials. By discretizing the cross-section of thewaveguide into a number of triangles, an eigenvalue problem isderived. A general program based on Arnoldi’s method andARPACK has been written using node and edge elements toapproximate the .eld. A serious problem in the FEM was theoccurrence of spurious solution, that was due to impropermodeling of the null space of the curl operator. Therefore edgeelements has been chosen to remove non physical spurioussolutions that arises. Numerical examples are given for homogeneous andinhomogeneous waveguides, in the homogeneous case the resultsare compared to analytical solutions and the right order ofconvergence is achieved. For the more complicated inhomogeneouswaveguides with and without striplines, comparison has beendone with results found in literature together with gridconvergence studies. The code has been implemented to be used in an industrialenvironment, together with full 3-D time and frequency domainsolvers. The2-D simulations has been used as input for full3-D time domain simulations, and the results have been comparedto what an analytical input would give. / NR 20140805