The objective of structural optimization is to maximize the performance of a structure or structural component. Optimal structural design is driven by the limited material resources, environmental impacts and technological competition which demand lightweight, low-cost and high-performance structures. An optimal design is defined as the best feasible design that satisfies the prescribed performance criteria. Design automation is a fusion in current engineering practice and has the ultimate goal of improving productivity and enhancing design capabilities. With advances in high-speed computers, structural optimization has the potential to become an automated design tool for practicing engineers in aeronautical, mechanical, automotive and civil engineering industries.