A systematic approach for integrated computer-aided design and finite element analysis of functionally-graded-material objects

Computer-Aided Design (CAD) and Finite Element Analysis (FEA) of Functionally-Graded-Material (FGM) objects are generally regarded as separate domains of interest in CAD and Computer-Aided Engineering (CAE) community. Such a separation of CAD modeling and FEA of FGM objects makes it cumbersome and tedious for both designers and engineers to exchange the necessary information in the entire design process. Without appropriate CAD models, complex material distributions can hardly be represented and the FGM objects under examination remain simple in material variations (e.g. unidirectional gradations). With CAD modeling tools only, the end users are still uncertain whether or not the designed objects can really meet the functional requirements in terms of structural, thermal or other prescribed properties. This paper proposes a systematic approach to integrate these domain-dependent design tools in FGM object design. Integrated solutions to CAD modeling and property analysis of FGM objects are utilized to design complicated (bidirectional or even tri-variate) FGM objects. Complex FGM distributions are encoded into the proposed Heterogeneous Feature Tree (HFT) structure; and the material compositions of a given point of interest are interrogated from the CAD models at runtime. Integrated FEA of FGM objects are then carried out by establishing a link between the proposed CAD modeler (CAD4D) and a commercial FEA package (COMSOL Multiphysics). Four different (three unidirectional and one bidirectional) FGM objects are modeled with traditional analytic function based approaches and the proposed methods. Under the same thermal and mechanical conditions, the properties of each model are compared in terms of temperature fields, residual thermal stresses and the strain energy densities. Results show that the proposed approach can facilitate the design of complex FGM objects in a systematic way. (c) 2006 Published by Elsevier Ltd.