Multiscale Modelling of Metallic Materials
Automotive manufacturers are in the need of suppliers who can develop cost efficient, optimized solutions and products with high customer value in a sustainable manner. In the long run the winning suppliers will be the ones who can realize an integrated perspective of their alloy, process and product development. The integrated perspective requires, quite generally, quantitative models, where as many quantitative links as possible must be established, so that needs with respect to a product’s cost and performance can be addressed along the value chain. Further, quantitative links and tools are required at all levels to reduce development time and costs (e.g. reduced engineering costs, reduced tooling/trimming, reduced number of prototypes, optimised performance/weight ratio).
During the later years rather accurate phenomenological constitutive models of metals have been developed and made available in commercial FE codes. These models represent the macroscopically observed behaviour (e.g. work hardening, anisotropy, process effects) on the basis of continuum mechanics. They do, however, not provide any information about the physical mechanisms responsible for the observed material response. Hence, the models do not contribute in enhancing the understanding of micro-mechanisms of plastic deformation and offers limited action upstream in the material processing chain. Another complementary approach consists in looking at the metal, or polycrystal, from a physical point of view. In this approach the material response is described on the basis of the elementary mechanisms governing the macroscopically observed phenomena. This approach is required for the design of optimised process chains, for the development of next-generation phenomenological models, and for reducing material characterisation costs. The physical models are often computationally expensive and can not replace the phenomenological models. Instead an optimised use of the models at various scales must be searched.