Modeling and processing of functionally graded materials for rapid prototyping

In this paper, we present an approach to model and process functionally graded material objects by integrating material information along with geometry information in the heterogeneous solid model. Geometry modeling of the objects is done in the CAD system and the STEP standard exchange format is adopted to exchange geometry information between the CAD system and heterogeneous solid modeling system. For material modeling, reference entities were selected and material distribution information in terms of distance functions were specified together. The material information was incorporated with geometry information by attaching distance functions to reference entities as their properties. In processing a heterogeneous solid model, the continuous material distribution is discretized in 2D space rather than in 3D space and only material distribution functions are saved in slice files. The slicing process goes along with the manufacturing process of heterogeneous objects concurrently. Therefore, much memory can be saved. Two examples are described. (C) 2003 Elsevier B.V. All rights reserved.