SHELL OR PLATE IDEALIZATION ON A POLYHEDRAL MODEL FOR FINITE ELEMENT ANALYSES

摘要

Very often, geometric transformations are required to adapt the geometry of a component to the requirements and hypotheses of a structural model in order to generate a Finite Element (FE) mesh suitable for modeling some physical phenomenon. This co-called idealization process is usually time consuming. This paper introduces a new set of operators to perform this preparation phase. The operators proposed are based on a polyhedral representation of the component to enable structural analyses to be integrated at various stages of the design process without requiring a model issued from a CAD system. The operators fit into an approach where geometrical criteria and mechanical ones are distinguished. Here, a first set of geometric operators is described and mechanical criteria are highlighted to set their relative positions. Two distinct stages are set up in applying geometric operators: firstly, candidate areas reflecting plate or shell morphology are identified and transformed into open surfaces ; secondly, the connections between the shell or plate elements are addressed through mechanical and geometrical criteria to allow the analyst to express the hypotheses he (resp. she) requires. Across these stages, the continuity and integrity of the model is always preserved, which enables a wide variety of treatment of the connections between the plate or shell elements, as it is often required when modeling structures. Finally, examples are provided to illustrate the efficiency and the potential of the approach proposed.