3372. Applications of Topology Optimization for Weight Reduction During Preliminary Design

Paper

Abstract

Weight reduction of current designs can be achieved through sizing optimization by reducing thicknesses with constraints on stress; stiffness, and frequency. Unfortunately, the weight reduction is usually just a few percent. A more effective approach to weight reduction is to define an optimum topology (layout) during the preliminary design stage. For example, three small diagonal reinforcement ribs may be more effective than two large horizontal ribs if the load path is diagonal. Another example is the number, size, and location of lightening holes. If the number and location of these holes is predetermined, weight reduction can only be achieved through changing the size of the holes. Much greater weight reduction can be achieved if the correct number of holes in the correct locations and of the correct sizes is used.
In this paper a finite element based structural topology optimization software program, Altair OptiStruct?. is used to detennine optimum layouts for aerospace, automotive, and consumer goods structures. This software program determines optimum topologies of components subject to weight, stiffness, and frequency limits. Examples will be shown and the weight reduction and cost benefits discussed. The impact of manufacturing constraints, such as stamping die and casting mold removal will be discussed. In addition, the optimal design of stamped ribs in sheet metal structures (topography optimization) will be introduced.
By using mathematical optimization techniques in conjunction with finite element based structural analysis, the optimal topology and topography of designs can be achieved. By using this approach during the preliminary design phase, significant weight can cost reductions can be achieved.