Mechanical Criteria for the Preparation of Finite Element Models

The use of CAD in design makes it possible to represent complex components “as manufactured” with a great number of details. A transformation of such models into Finite Element (FE) models often generates a much too large number of elements to be used directly. Therefore, the removal of shape details is required to prepare a FE model. Often, these shape transformations are required to suit the hypotheses of the FE analysis. The user must control this simplification process in order to ensure sufficient accuracy of the FE results. In this paper, different criteria are studied to evaluate ‘a priori’ the quality of a shape simplification process like variations in volume, area and center of gravity when the input shape is generated from CAD models. These criteria can be related to different mechanical properties and, according to the simulation objectives, the analyst can assign threshold values to the chosen criteria. These criteria can be evaluated locally over the shape of a component to provide a qualitative analysis of shape changes. Such an approach has been applied in the framework of polyhedral models.