Simulations of production by forming and welding, and crash testing of an aluminum crash management system have been carried out. A numerical tool/interface is also developed for modeling, simulating and evaluating the material flow, the design concepts and fabrication processes continually, accurately and fast.
In the present paper, the fabrication processes of the Audi A1 crash management system are studied. The system consists of a stretch-bent extruded beam, a towing nut, two extruded crash tubes and two plates that are welded together.
In order to perform analyses efficiently, this study employed a common set of solid elements for modeling the forming, welding and crash processes.
The forming simulation has been performed in IMPETUS Afea Solver. The solid elements have been transferred flexible from coarse single order elements into the fine higher order elements in different stages of the design. In this way, it is possible to quickly capture the key concepts of the tool design, and to ensure that the details of the product and the requirements of the tooling can be correctly predicted. The welding simulation has been performed in Weldsim. It combines a thermal, a mechanical and a metallurgical model. The thermal history, the welding deformations, the hardness and the microstructure distribution, the residual stresses and the distortions in the system are evaluated after a welding simulation. Through the welding simulation, the effect of the welding fixtures and the welding heat input can be assessed.
Result fields from the welding simulation include the yield stress varying through the heat affected zones. This result field is imported to and applied in the crash simulation.
Crash simulation is carried out with the information of changes in material performance caused by the welding heat.
Through a crash simulation the ability of the system to perform correct deformation and fracture modes is verified.