Automated Finite Element Analysis in a Knowledge Based Engineering Environment

Abstract

§Efficient use of finite element based analysis in a knowledge based automated design environment requires the solution of two problems. First, it must be ensured that for every instantiation of a parametric product model, the geometry is segmented (discretized) in such a way that proper element connectivity can be assured. Second, since changes in product variables (dimensional changes) and changes in product parameters (configuration changes) will lead to changes in the mesh topology, the product attributes (e.g. material and supports) must be linked to the product geometry and not to element meshing. This paper shows that the segmentation process normally carried out by FEM experts manually, can be implemented with Knowledge Based Engineering (KBE). As a result it is guaranteed that the geometry associated to any instantiation of the product model is properly segmented and the connectivity issue is handled in a robust way. This paper shows that the dependency of the FEM model definition on the underlying mesh can be solved by adding information and/or knowledge to the geometric data from the KBE tool. In a traditional CAD based design environment, the knowledge generated in the geometric design stage is inaccessible to the FEM pre-processing process due to the fact that data transfer formats are incapable of capturing this knowledge. It is shown that in a KBE environment information/knowledge stored in the product model can be extracted and made accessible. Finally, it is shown by an elaborate example of a rudder design case that the combination of properly segmented geometry and the knowledge extracted from the product model together with a newly developed, Python based Knowledge Based Engineering Finite Element Analysis tool allows for the flexible incorporation of automated FEM analysis in a multi-disciplinary design environment.