Ph.D. Proposal Presentation by Hongqing Vincent Wang
Friday, March 5, 2004

( Dr. David W. Rosen, Chair)

"A Design Synthesis Method for Low Volume Ratio Structures"

Abstract

Geometry optimization has a great impact on the performance of low volume ratio structures, such as least-weight components, micro movement-amplifier and negative Poisson’s ratio material. Low volume ratio structures are those with a big portion of space occupied by void instead of solid material. They are divided into two categories, rigid structures and flexible structures. Rigid structures are designed for least weight, high strength and stiffness. Flexible structures are designed for certain compliances to transform motion and forces. Topology optimization plays a significant role in geometry optimization. Various topology optimization methods have been developed and applied successfully. Typical methods are ground truss approach, homogenization method, and topology synthesis. But those methods have their limitations in terms of obtaining robust design, automating design process, and utilizing computation resources. Those limitations are more evident to design 3D structural systems.

The research objective of this proposal is to investigate a design synthesis method of low volume ratio structures. As a result of this research, low volume ratio structures can be designed with higher efficiency, accuracy, robustness and reliability. Four research questions will be raised in terms of material representation, structural analysis, design synthesis, and manufacturing. Unit trusses, as microstructures, are proposed to represent the material distribution of low volume ratio structures. Unit truss and whole structural system will be analyzed through creating and solving their analytical models. A synthesis process using robust topology exploration method will be proposed to search for a robust close-to-optimum design of low volume ratio structure. The manufacturing processes of the low volume ratio structures will be investigated and their limitations will be considered at the early design stage.