基于特征造型技术的三维CAD系统目前已广泛应用于产品设计,同时CAE在产品设计与优化中也起到了越来越重要的作用.而有限元是最为广泛使用的CAE方法之一.由CAD系统建立的模型在进行有限元分析之前,通常需要根据分析需要对模型进行简化,如何分析模型简化前后对有限元计算结果的影响程度是CAD模型到CAE模型自动转化的首要步骤.将模型因特征的简化而形成的各种状态的模型称为多态模型.针对确保一定分析精度,节省计算资源的需求,根据有限元误差理论提出了分析不同简化模型对有限元分析结果造成的误差的方法,且通过数据实例得到验证,根据误差分析方法提出模型误差层次的概念,为有限元领域中多态模型的生成提供了新的思路.

3D computer aided design (CAD) system based on feature-based solid modeling technique has been widely used for product design recently. At the same time, CAE also plays a more and more important role in product design and finite element method is one of the most popular CAE methods. The models built by CAD systems usually need simplification before finite element analysis according to precision need. How to analysis the degree of simplification is an essential problem in automatic transformation from CAD model to CAE model. Models of different degree of simplification are called Multi-state Model. Considering the need of economizing hardware resource and ensure the appointed correction precision at the same time, this paper proposes a measurement method of the error of different simplification models according to FEM error analysis theory and then validates that by numerical results. Based on the measurement method, the concept of Level of Error is proposed, which provides a new way of getting Multi-state Model in FEM field.

Supported by the National Natural Science Foundation of China under Grant No.60673028 (国家自然科学基金)