Simulation of the process chain from forming to crash taking into account stochastic aspects
The local mechanical properties e.g. flow stress and fracture strain in an automotive component manufactured by deep drawing are inhomogeneous due to different local deformation degrees which affect the component behavior under crash loading. A reasonable approach for modelling the deformation and damage behavior of a component produced by deep drawing is a coupling between forming simulation and crash simulation. However, many questions are still open for this approach, e.g. how strong the crash behavior of a component depends on the manufacturing process and the applied modelling methods and which damage model should be used for an integrated simulation. Moreover, it is necessary to quantify the influence of additional stochastic scatter of material properties on the numerical prediction of component behavior for crashworthiness analysis. Until now there are few results in the literature about the application of an efficient stochastic analysis for modelling of a process chain. In this work a basic model was developed for modelling the process chain from forming to crash. Deterministic and stochastic scatters of the material properties in a component of the steel ZStE340 were experimentally characterized. The influences of pre-strain and pre-damage caused by forming on the crash behavior of the automobile component were investigated. The influences of loading history and triaxiality on damage behavior were quantified. A general material model which describes anisotropy and damage was developed and implemented for forming and crash simulations. To validate the applied concept component tests under bending with superposed tension were performed and simulated. This basis model was used for a stochastic analysis based on the singular value decomposition (SVD) method.