A Hierarchical, Heterogeneous Material CAD Model with Application to Laser Sintering

Variations in laser irradiance and local temperatures in laser sintering cause variations in porosity and material microstructure, which can affect mechanical properties of a part. From the design perspective, it is important to model microstructures, mechanical properties, and their relationships so that parts can be analyzed and designed taking into account their asmanufactured condition. In this paper, we propose the modeling of part geometry and microstructure by using a new hierarchical modeling method. A surfacelet transform is introduced to model microstructure. The application of image processing methods enables multi-resolution representations of microstructure. Combined with methods from computational materials design, low resolution microstructure representations can be used to compute effective mechanical properties. The models and methods are demonstrated on two examples, a simple fiber-reinforced composite and a laser sintered nylon-12 material.