Preparation of Finite Element Models: The Use of an a Posteriori Mechanical Criterion

Abstract

A geometrical model needs to be simplified to perform a FE (Finite Element) analysis. Several tasks of shape processing are required during the FE model preparation phase. An appropriate geometric model and a suitable set of geometric and mechanical operators may significantly improve the efficiency of the whole process. Our approach is based on the use of a reference geometric model that is the polyhedral representation of a component. To simplify the component shape, we utilize some geometric operators associated to mechanical hypotheses, so that all the component shape changes take into account the mechanical hypotheses related to the FE model. Since a priori criteria acting before the FEM solving process cannot efficiently quantify the influence of a shape simplification on the accuracy of FE simulation results, a mechanical a posteriori criterion has been implemented, which analyses the impact of shape changes on the simulation to tune the simplification process. Therefore, we perform a first FE computation on the simplified model and use the results to assess the mechanical influence of shape simplifications that have acted on the model. If some details prove to have influence on the mechanical behaviour, the model on which the FE analysis is performed needs to be redefined. Therefore, we are able to adapt the model according to a desired accuracy of the analysis results. In this article, we describe all the process that has to beset up to perform this adaptive modelling of components.