Computer-aided design of heterogeneous objects

• Authors: Xinyu Kou
• Venue: Computer-aided design of heterogeneous objects
• Year: 2006

Heterogeneous object design is an active research area in recent years. This research focuses on computer-aided design issues in heterogeneous object design. Systematic studies on data representations, computer visualization, finite element analysis and rapid prototyping of heterogeneous objects are presented. Complex representational capabilities reflect the practical usefulness and the descriptive power of a particular modeling system. In this research, generic and unified data representations are proposed to represent complex heterogeneous objects. A hierarchical representation is proposed to model compound material distributions. This representation closely integrates the material information into 1D/2D geometric features, and complex 3D objects can be hierarchically constructed upon the lower-dimension heterogeneous features. Based on this hierarchical representation, flexible and compound material distributions can be modeled with the proposed Heterogeneous Feature Tree (HFT) structures. To represent generalized complex heterogeneous objects which have simultaneous geometry intricacies as well as compound material distributions, a more general Heterogeneous Cellular Representation (HC-Rep) is further extended. HC-Rep takes advantages of the non-manifold cellular representations to model the complex geometries of the objects and utilizes the underlying topological information in material modeling. With the aid of the cell adjacency information and attribute based reasoning, smooth, complex and versatile material distributions can be defined upon the intricate geometries. To properly render heterogeneous objects in computers, systematic methodologies for heterogeneous object visualizations are proposed. Efforts to generate faithful, high quality computer visualizations at interactive rate are presented. To avoid abrupt material transition effects, boundary sub-faceting approaches are proposed; to speed up the visualization process, adaptive boundary sub-faceting schemes are developed. To evaluate the object's properties in terms of prescribed functional requirements, Finite Element Analysis (FEA) of heterogeneous objects is conducted by establishing a link between the proposed modeler (CAD4D) and a commercial FEA package (FEMLAB). Data communications are elucidated with implementation details. To verify the object's validity, Rapid Prototyping (RP) of heterogeneous objects is applied. Data structures and algorithms are explained through virtual prototyping processes and validated with the commercial 3D Printer system. All these proposed schemes and methodologies have been successfully developed and implemented in a prototype software package---CAD4D. The prototype modeler proves the validity of the presented data representations and methodologies and can be used in practical downstream applications for design, analysis and prototyping of heterogeneous objects.