Process Chain Forming to Crash: Efficient Stochastic Analysis

During the fabrication of products, important material and process parameters, geometry and also external influences (e.g. room temperature) can vary considerably. It is known that they can have a substantial, even critical influence on the quality of the resulting products. Therefore, software tools and strategies supporting an efficient and thorough analysis of sensitivity, stability and robustness aspects as well as a multi-objective robust design-parameter optimization are necessary. This is especially true for parts of a car with a potentially critical influence in crashes as, for instance, the B- pillar which consists of several formed and connected blanks. We propose a new strategy, built upon several software tools as well as new material models, supporting an analysis of variations for the process chain forming to crash. The strategy roughly consists of the following parts and software tools: forming simulation (LS-DYNA) - - parameter sensitivity analysis (DesParO) - reduction/compression of input and output (DesParO) mapping (SCAImapper) - crash simulation (LS-DYNA) - - stability analysis (DIFF-CRASH) - sensitivity analysis (DesParO) - reduction/compression of input and output (DesParO) multi-objective robust design-parameter optimization (DesParO) - comparisons with physical experiments (as far as available) - Efficient, novel methods are proposed and employed for sensitivity analysis of simulation results on fine grids depending on parameter variations, for a reduction of the design space and the simulation results as well as for mapping an appropriately constructed data base of most influencing trends, not only comprised of thicknesses and strains, but also damage information. Including the latter turns out to be a crucial point. Results are shown, in particular, for a ZStE340 metal blank of a B-pillar. Comparisons to experiments demonstrate the abilities of the strategy proposed.

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