Developing design guidelines for load carrying sheet metal components with regards to manufacturing method

Abstract: Load carrying brackets in the engine room of Scania's busses are almost exclusively manufactured through bending of sheet metal. It is believed that pressing, rather than bending, could result in lighter components. Lighter components mean less weight for the bus to transport and could, for example, result in allowing additional passengers on the bus.The problem definition included producing guidelines regarding the two manufacturing methods of sheet metal: bending and pressing. The guidelines were designed to aid, mainly novice, design engineers in early stages of component development. Existing components were FEM-analysed and redesigned to investigate the potential weight reduction for using pressing rather than bending. Lastly, on the topic of weight reduction, the potential of using carbon fibre reinforced polymer for load carrying components, such as brackets, was evaluated. The information for the guidelines and the evaluation of carbon fibre reinforced polymers were gathered through a series of study visits and a literary review.The guidelines were presented as a document, comprised of general considerations and rules of thumb. They are to be stored as a living document, continuously complemented and updated. The hope is to reduce the amount of unnecessary feedback from suppliers, and help designing cost-efficient components. The result from the modelling showed that weight reduction was possible by redesigning the investigated parts for pressing rather than bending. It was concluded that the most prominent weight reduction was achieved for components where removal of a limiting weld was successful. Further investigations should be conducted on a wider variety of parts to make the results more reliable. As for the carbon fibre reinforced polymers, the investigation indicates that a mere substitution of material is not cost-efficient for several reasons. To successfully implement use of carbon fibre reinforced polymers, larger and innovative solutions that utilises all the favourable properties of the material is required. Further studies should hence be initiated, with the focus of combining multiple purpose designs.