This bachelor thesis has been carried out in collaboration with Nitator at Oskarström, Elvis Vodenicarevic has acted as the contact person from the company. Håkan Petersson has acted as responsible supervisor from Högskolan i Halmstad. The purpose of the project is to automate the welding process for two articles. The considered method and equipment will result in cost savings and quality assurance. Currently the welding operation is done manually, where the purpose of the project lies within automation of the welding process. The process will be mostly handled by robots the only human interaction, except for service and maintenance, will be operators feeding material to the magazine. During the time spent at Halmstad University, the students have accumulated the information and experience in design and production that have been the basis for the design of the work. The understanding is based on courses that include mechanics, strength, production development, machine elements, solid modeling and structural analysis. The foundation of the working methodology is based on Fredy Olsson's methods of principle and primary construction. With these methods as support, a complete fixture and magazine has been designed as part of an automated welding process. During the development, the strength and fatigue resistance of the components were checked in Catia V5's analysis function Generative structural analysis. This is to ensure a product that is capable of the loads that occur. This report will mainly deal with the work that has been done regarding the development of the fixture solution. From page 20-23 comes a summary of the most vital parts of the design of the magazine.

When working with complex aircraft design it is necessary to be able test configurations easily. At Saab this is done in several ways. When looking at the weapons integration on the Gripen Aircraft, clearance analysis (called feasibility studies at Saab) are created to evaluate if new external stores can be mounted. This is done manually in CATIA by measuring and evaluating the result. To ease the work when performing these repetitive tasks, it is possible to take advantage of Knowledge Based Engineering, KBE. This thesis revolves around implementing KBE in the process. The approach is to create a configurator that can handle the different external stores and perform the required tasks. The end result is a configurator with a Graphical User Interface, GUI, in which the user gets help with the feasibility study and which requires light manual input from the user. The configurator performs the study and produces a Word report for the user to examine. The resulting time saving is around 75 to 80 percent from the original process. The conclusion is that the configurator can facilitate the feasibility studies at Saab by reducing the time and lower the threshold for the user. Even though the process is not fully automated, the configurator is judged to perform at a satisfying degree.

Design decisions have a large impact early in the design process. Optimization methods can help engineers improve their early decision making, however, design problems are often ill-posed for optimization at this early stage. This thesis develops engineering methods to use optimization during embodiment design, despite these difficulties. One common difficulty in designing mechanical systems is in handling the effects that design changes in one subsystem have on another. This is made more difficult in early engineering design, when design information is preliminary. Increased efforts have been made to use numerical optimization methods in early engineering design – because of the large impact early decisions have on subsequent development activities. One step toward executing meaningful optimizations in early design is the development of an optimization framework to be used when conditions are expected to change as the design progresses and new information is gained. This thesis presents a design framework that considers such change by subjecting the parametric updating of CAD models to optimization criteria specific to the problem at hand. Under the proposed framework, a part or subassembly is parametrically modeled in CAD; when changes are made to the subsystems that interact with the part or subassembly, it is then updated subject to design objectives and constraints. In this way, the updated part or subassembly satisfies system and subsystem level optimization criteria, reducing the need for the designer to react to design changes manually. It is used to reduce the weight of a Formula SAE suspension rocker by 18%, demonstrating the utility of this framework. Next, we develop methods to help engineers by giving them options and helping them explore during configuration generation. The design of multiple-bend, progressive-die-formed springs typically comprises four steps: (i) functional specification, (ii) configuration generation, (iii) configuration selection, and (iv) detailed shape and size optimization. Configuration generation fundamentally affects the success or failure of the design effort. This presents an important problem: by not generating potentially optimal configurations for further development in detailed design, the designer may unknowingly set the design on track for sub-optimal performance. In response, a method is developed that improves configuration generation. Specifically, an optimization-based spring configuration generator – without which, the generation would typically be based solely on designer creativity, experience, and knowledge. The proposed approach allows the designer to explore numerous optimization-generated spring configurations, which feasibly satisfy the functional specifications. The feasibility study is carried out before a final configuration is chosen for detailed development. Thus streamlining the designer's efforts to develop a design that avoids sub-optimality. We use the feasibleconfiguration generator to identify twenty-two electrical contact spring configurations. All twenty-two of the configurations satisfy the design's functional specifications. Two important concepts that improve decision making in early design were chosen. First, is the concept of a paremetric CAD based framework. Second is the concept of generating iso-performing design solutions. A numerical computer-based application is explained that takes advantage of these two ideas. A genetic algorithm topology optimization framework with the ability to converge to iso-performing solutions was integrated with CATIA V5. This application is demonstrated on a Formula SAE frame where it develops a pareto frontier of designs, expands upon one compromise design by producing iso-performing solutions, and automatically produces designs with the same performance after a parametric suspension change.

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Detta examensarbete handlar om finita element analys av svetsade förband i korgen på Volvo dumpern A40E. Det genomfördes i samarbete med Volvo CE i Braås. Uppgiften var att ge företaget en lämplig lösning för att minska mängden svetsskarvar på den främre delen av lastenheten. För att uppnå detta har en rad analyser genomförts med hjälp av CATIA och ANSYS på både de befintliga och de justerade (potentiella ersättare) svetsade förbanden. Analyserna visar att utmatningshållfastheten av svetsade förband huvudsakligen beror på inbränningsdjupet. Med andra ord, förstärka svetsförband genom större inbränning är mer fördelaktigt än att använda mer svets på utsidan. Slutsatsen blev att både produktionstid och kostnad kan minskas genom justering av de svetsade förbanden. Eftersom svetsförband på lastenheten är sammankopplade bör mer omfattande studier som inkluderar alla svetsar genomföras för att uppskatta effekterna av liknande justeringar. / The work presented in this master thesis is about the finite element analysis of the welded connections in load carrying unit of the articulated hauler, Volvo A40E. It was performed in cooperation with Volvo CE in Braås. The task was to provide the company with an appropriate solution to reduce the amount of weld used on the front part of the load carrying unit. To accomplish this, a series of analyses utilising CATIA and ANSYS was performed on both existing and adjusted (potential replacement) welded connections. The analyses brought to light the fact that the fatigue resistance of welded connections significantly depends on the penetration depth. In other words, reinforcing the welded connections by deeper penetration is more beneficial than providing support from outside through thicker weld. It was concluded that applying adjusted welds lessens both the production time and cost. Nevertheless, since the welds on the load carrying unit are correlated; more extensive studies covering all welds should be carried out to estimate the impacts of similar replacements.

<p>Detta examensarbete handlar om finita element analys av svetsade förband i korgen på Volvo dumpern A40E. Det genomfördes i samarbete med Volvo CE i Braås. Uppgiften var att ge företaget en lämplig lösning för att minska mängden svetsskarvar på den främre delen av lastenheten. För att uppnå detta har en rad analyser genomförts med hjälp av CATIA och ANSYS på både de befintliga och de justerade (potentiella ersättare) svetsade förbanden. Analyserna visar att utmatningshållfastheten av svetsade förband huvudsakligen beror på inbränningsdjupet. Med andra ord, förstärka svetsförband genom större inbränning är mer fördelaktigt än att använda mer svets på utsidan. Slutsatsen blev att både produktionstid och kostnad kan minskas genom justering av de svetsade förbanden. Eftersom svetsförband på lastenheten är sammankopplade bör mer omfattande studier som inkluderar alla svetsar genomföras för att uppskatta effekterna av liknande justeringar.</p> / <p>The work presented in this master thesis is about the finite element analysis of the welded connections in load carrying unit of the articulated hauler, Volvo A40E. It was performed in cooperation with Volvo CE in Braås. The task was to provide the company with an appropriate solution to reduce the amount of weld used on the front part of the load carrying unit. To accomplish this, a series of analyses utilising CATIA and ANSYS was performed on both existing and adjusted (potential replacement) welded connections. The analyses brought to light the fact that the fatigue resistance of welded connections significantly depends on the penetration depth. In other words, reinforcing the welded connections by deeper penetration is more beneficial than providing support from outside through thicker weld. It was concluded that applying adjusted welds lessens both the production time and cost. Nevertheless, since the welds on the load carrying unit are correlated; more extensive studies covering all welds should be carried out to estimate the impacts of similar replacements.</p>

Ett ljudfenomen som uppstår i samband med luftkomprimeringen i den nya D7 motorn har uppmärksammats som ett problem av kunderna. Ljudfenomenet som resonerar i hytten bidrar till en obehaglig arbetsmiljö. Uppdraget har i sin tur varit att utveckla en luftkompressormonterad ljuddämpare mot en kravspecifikation som eliminerar detta fenomen. Med hjälp av diverse verktyg och en spiral produktutvecklingsprocess utfördes ett flertal iterationer av dem koncept som kan tänkas lösa problemet. Dessa iterationer konstruerades i mjukvaran CATIA V5 för att sedan beställas in som fysiska prototyper i materialet Pa12. För att bekräfta prototypernas funktionalitet utfördes simuleringar samt fysiska tester. Det resulterande arbetet blev ett konceptförslag till Scania CV AB som uppfyller kravspecifikationerna. Lösningens ljuddämpningsförmågan reducerade ljudfenomenet med 73% i genomsnitt. Med hjälp av observationer och analyser under de fysiska testgenomförandet uppmärksammades komplikationer som bör åtgärdas. Det mest kritiska med det nuvarande konceptet är dem vibrationer som uppstår. För att åtgärda detta problem kommer det krävas ytterligare infästningspunkter på motsvarande sida till de nuvarande. All mätdata i denna rapport är modifierat. Detta för att skydda känslig information. / A noise phenomenon that arises in connection with air compression in the new D7 engine has been noted as a problem by the customers. The sound phenomenon resonates in the cabin contributes to an unpleasant work environment. The mission, in turn, has been to develop an air compressor-mounted silencer against a requirement specification to eliminate this phenomenon. Using various tools and a spiral product development process, a number of iterations were made of those concepts that could solve the problem. These iterations were engineered in the CATIA V5 software, then ordered as physical prototypes in the material Pa12. To confirm the prototypes' functionality, simulations and physical tests were performed. The resulting work became a concept proposal for Scania CV AB that meets the requirements specifications. The solution managed to reduce the sound phenomenon by 73% on average. With the help of observations and analyzes during the physical test implementation, complications were noted that should be addressed. The most critical on the current concept is the vibration that occurs. To fix this problem additional attachment points will be required on the corresponding side to the current ones. All data in this report have been modified. This is to protect sensitive information.

Detta examensarbete undersöker möjligheten att tillämpa tidiga och ej så beräkningstunga CFD-simuleringar (’Computational Fluid Dynamics’) för optimering av gasväxlingskomponenter tidigt i produktutvecklingsprocessen. Examensarbetet har innefattat framtagande av generellt applicerbara inställningar och riktlinjer vid modellering av gasväxlingskomponenter med programvaran OpenFOAM, optimerade för att nyttja så låg beräkningskraft som möjligt men fortfarande erhålla tillräckligt noggranna och pålitliga resultat. Rapporten ger en teoretiskt genomlysning med motivering av simuleringsrelaterade val i OpenFOAM i syfte att validera och efter behov justera de inställningar och parameterval ansatta i det befintliga Excel skriptet – framtaget av avdelningen med ansvar för avgasefterbehandlingssystem – som automatiserar uppställningen av OpenFOAM:s simuleringsrelaterade filstruktur. Detta i syfte att erhålla och säkerställa pålitliga resultat vid användning av skriptet anpassat för simulering av gasväxlingskomponenter. Rapporten redovisar även bakomliggande analyser för olika inställningar och val i OpenFOAM i syfte att tjäna som välgrundade riktlinjer genom hela CFD-processen; såsom för skapande av geometriska modeller, generering av volymsnät, åtgärder för att säkerställa konvergens samt uppställning och tolkning av resultatet. En av examensarbetets leveranser är en metodbeskrivning utformad med praktiska riktlinjer för genomförandet av hela CFD-processen med avsedda programvaror samt med tillhörande praxis avseende simuleringsrelaterade val genom processen. Ett antal genomförda fallstudier i examensarbetet visar att OpenFOAM har potential att utföra initiala och indikativa simuleringar för att mer tidseffektivt möjliggöra en bredare idégenerering i konceptutvecklingsfasen. / This thesis investigates the possibility of applying early and not so computational heavy simulations using Computational Fluid Dynamics (CFD) for optimization of gas exchange components early in the product development process. The scope of the thesis includes the development of generally applicable settings and guidelines – documented in a methodology – when modelling gas exchange components with the software OpenFOAM, optimized to use as low computational power as possible but still obtaining sufficiently accurate and reliable data. The report consists of a theoretical study and motives for simulation-related choices in OpenFOAM in order to adjust and validate the settings and parameter choices applied in the existing Excel script – developed by the department responsible for exhaust aftertreatment systems – that automates the set-up of OpenFOAM's simulation-related file structure. This in order to obtain and ensure reliable results using the script adapted to the environment for gas exchange components. The report also presents underlying analyses for different settings and choices in order to serve as well-founded guidelines throughout the CFD-process; such as the creation of geometric models, the generation of mesh, measures to ensure convergence, and the set-up and interpretation of the results. One of the deliverables of the thesis is a method description designed with practical guidelines for the entire CFD-process with intended software’s and with associated best practices in regards of simulation-related choices throughout the process. A number of case studies – that has been simulated in this thesis – show that OpenFOAM has the potential to perform initial and indicative simulations enabling a more time-efficiently and broader ideation in the concept development phase.

Work chair is considered as an important element for the users to improve comfort in work environment. An ergonomic chair design and engineering is therefore considered very important for its usability and comfort view of point for the users. The aim of the thesis is to improve the mobility and ergonomics of the existing chair in all aspects. Ergonomically designed chairs are important for long time seated workers to increase their productivity and also to reduce low back injuries which arise due to the poor design chairs in ergonomic aspects. In addition, ergonomically designed chairs help to increase the seating comfortability of the chair users. QFD and waterfall model was followed for the work execution. In this paper, we discuss a design of an ergonomically efficient chair with simple adjustments which gives more comfortability. This will give us a better likelihood to stay in a neutral position. The Ergonomics of the chair is improved in various steps. This thesis focuses on many ideas in which some of them are implemented and evaluated.

The aim of this diploma thesis is to create useful reference models of the glider L-23 Super Blaník and their use for framework proposal technology of production, which will improve accuracy and reduce labor intensity of production. The introduction of the thesis describes history of glider and historical overview of geometry transmission in terms of structure. The next chapter of the thesis deals with the description of reference models and rules of their creation. Section describing coordinate systems is closely linked with the previous chapter. Another section of thesis is dedicated to the importance of reference models in the product lifecycle. The creation and tuning of reference models of glider is described in the next chapter of thesis. The penultimate chapter deals with experiment, which allowed verification of reference model and product. The conclusion of the thesis describes proposed technology of production where used verified reference models and modern tools of CAD systems refine and facilitate production. The main objective in designing of reference models was the definition of high quality and usable surfaces. Also proposal technology of production was processed in order to ensure the improvement and simplification of manufacturing process.