Syftet med rapporten var att utveckla en transportvagn hos företaget Arronet Teknik AB där ett grundkoncept redan var uppfunnet sedan tidigare. Uppdraget skulle utföras för att effektivisera företagets nuvarande plåttransport. Transportvagnens huvudsakliga syfte var att transportera plåt på ett säkert, ergonomisk och praktiskt sätt från plåtlagerslokalen till produktionslokalen för beskärning. Eftersom produkten skulle sammansvetsas med metallrör, samlades litteraturstudier in i teorin för att identifiera vilket material som stålkonstruktionen ska konstrueras i. Materialet skulle ha god svetsbarhet och vara starkt föratt klara av tunga laster av plåt. Litteraturstudien innehöll även utformning av olikasvetsfogsdesigner och hur de implementeras i metallrörskonstruktioner. För att besvara frågeställning ett, som handlade om vilka krav som ställs på transportvagnen, utfördes en semi-strukturerad intervju i kombination med direkta observationer för att samla in kundkrav. Kundkraven omvandlades till produktkrav som därefter introducerades till produktutvecklingsprocessen. Frågeställning två handlade om hur transportvagnen kundekonstrueras för att uppfylla de identifierade kraven. För att besvara frågeställningen delades produktutvecklingsprocessen upp i två delar där koncept för drivna vagnar utforskades och koncept för en drivande vagn. Tester med FEM-simulationer och ostrukturerade intervjuer användes för att bestämma varsitt koncept. Arbetet resulterade i ett underlag för företaget med konstruktionsförslag för de påkopplade vagnarna, den drivande vagnen och andra komponenter som tillhörde transportvagnen. Resultaten analyserades och diskuterades därefter. / The purpose of the study was to develop a design proposition for a transport cart for Arronet Teknik AB where a basic concept already had been developed. The purpose of the task was to streamline the company’s current sheet metal handling process. The transport cart’s main purpose was to transport sheet metal in a safe, ergonomic, and practical way from the warehouse to the production premises for processing. Because the transport cart was to be welded together with metal tubes, literature studies had to be done for the theory, to identify the most common metals used in welded metal constructions. Hence the literature study contained different configurations of welding joints and how they integrate tubular constructions. To answer research question 1 which asked what the requirements of the transport cart was, a semi-structured interview in combination with direct observations was needed to collect customer requirements. The customer requirements where then translated into product requirements and then introduced into the product development process. Research question 2asked how the transport cart was to be constructed to fulfil the previously stated requirements. To answer the question the product development process was divided into two parts where one part contained the development of the driven carts and the other contained the drivetrain. Tests with FEM-simulations and unstructured interviews was used to decide upon the final concepts. The study resulted in proposed design for the company. Afterwards the results were analysed and discussed

This report presents the degree project for a master's degree in Mechanical Engineeringat Luleå University of Technology performed by Emma Olsson at GKN ePowertrain in Köping. The aim of the thesis was to develop a calculation method to evaluate fatigue ina weld due to torsion. During the degree project, two di erent calculation methods weredeveloped - An analytical method and a numerical method. The analytical method is based on a calculation method already used at GKN for calculatingfatigue due to rotary bending, but with the adaptations required for when the weld issubjected to torsion. For this method, Wöhler's curve, Goodman and Gerber mean stresscorrection and Palmgren-Miner's rule have been used. The numerical method was performed in the commercial software FEMFAT, which hasbeen developed to calculate, among other things, fatigue and safety factors. This is asimulation program the company in question has, but previously not used for this purpose. During the process of developing these calculation methods, areas such as mean stresscorrection, fatigue strength and weld classi cation have been studied, and appropriatesettings for the simulation.This resulted in two calculation methods whose results differ greatly from each other.The analytical method is a very conservative method in which the fatigue damage that iscalculated becomes very high and according to the damage value the weld will fail. Forthe numerical method, on the other hand, the fatigue is very low and, according to thedamage value, will not fail. Based on this, it can be stated that the numerical method is the method considered mostreliable and should be further investigated and  nally used. However, it is not possible togive a precis conclusion of whether the methods correspond to the reality, since no physicaltesting have been performed.