Combining forming results via weld models to powerful numerical assemblies

Forming simulations generally give satisfying results with respect to thinning, stresses, changed material properties and, with a proper springback calculation, the geometric form. The joining of parts by means of welding yields an extra change of the material properties and the residual stresses. Welding simulations are also possible to a very accurate degree, they are however very time consuming, even on large computer systems. Therefore it is not feasible to include a complete incremental welding simulation in the virtual model of car parts. Instead, simplified weld models are developed that retain the features needed for subsequent calculations (e.g. structural und fatigue calculations), but do not increase the computation time significantly. Thus, an accurate model for specific tasks can be achieved which includes both forming and welding. The objective of this paper is to show how the integration of the complete history of manufacturing of the single parts and its combination to larger car components, enhances the capabilities of the virtual model. This integration procedure must be adapted specifically to the different subsequent calculations in order to combine a maximum of reliability with a minimum of computer effort. In this paper it is demonstrated how the performance of a chassis part changes with the inclusion of both the plastic forming effects and the effects of welding as provided by the simplified weld models. The results are compared to the results of the same part where the manufacturing stages were neglected, which is industrial standard nowadays.