We characterize the mechanical properties of joints and assess them in terms of their deformation and failure behavior. A particular focus of our work is joint modeling for crash simulations, as this is the only way to analyze such a large number of different joints in the whole vehicle structure, thousands of them, and predict their capacity. Work is also carried out on predicting residual stresses and distortion in thermal joints with the aid of numerical welding simulations. By simulating joining processes such as punch riveting we are able to determine the aspects of the process that influence the joint properties.
© Photo Fraunhofer IWM
Substitute modeling for crash simulations
A reliable and practical description of joint failure in crash simulations depends on special elements, so-called substitute models and their input data. The Fraunhofer IWM has developed a simple, efficient substitute model and a technique for determining the failure parameters for spot welds. A material model has also been implemented for modeling the failure of adhesive bonds with parameters that have been determined from substance and joint samples and ...