The Challenge

The Finite Element Method (FEM) is a well established technique in a wide range of disciplines, most successfully applied in mechanical engineering. For example, in the automotive and aerospace industries the FEM is commonly used for structural design and the development of new products. It enables modern lightweight designs and facilitates the development and usage of new and highly specialized materials (composites, advanced aluminium alloys, high strength steels, etc.) as well as joining technologies (spot welding, adhesive bonding, etc.).

However the quality of FEM results strongly depends on the availability of appropriate material models that describe the nonlinear behavior and failure of these materials. The development and identification of new material models has become an increasingly complex and expensive process, partly as a consequence of the tradition of using purely analytical, physically motivated mathematical models for predicting material behavior.

In the common classical procedure for the development of material models it is the standard approach to propose an analytical draft for the material model (a hypothesis) based on the experience and know-how of a high level expert or on theoretical considerations. Subsequently a test plan is set up, which is focused to identify the parameters of the material model and verify the hypothesis. In the case of complex materials this approach has some flaws:

  • The hypothesis based bottom-up approach often leads to extensive trial and error scenarios, because with the complexity of the material it becomes harder and harder to meet reality with the hypothesis. Falsification of the hypothesis often causes a restart nearly from scratch.
  • The development effort grows exponentially with the complexity of the problem and the number of parameters contributing to the problem.
  • High level experts are not available arbitrarily and normally it takes a long time to develop one. Often it takes years to become familiar with special high tech materials.
  • In the daily standard project life there is rarely enough time for the scientifically neat development of proper material models. For a considerable number of materials and material behaviors suitable models cannot be confidently expected even in the medium term. At least some high level workarounds should be available quickly.

CoMModO is intended to overcome some of the above drawbacks!