Concurrent Design of Product-Material Systems Using Multilevel Optimization

Abstract

In traditional structural optimization, the geometric properties of the product are optimized for a specific set of material properties. This paper seeks to extend the domain of product optimization to also include the material modeling parameters by treating the product and material as a hierarchical multilevel system that can be decomposed and solved using the analytical target cascading (ATC) method. Two material models are considered here. The low-fidelity model is based on a simple elastic-plastic constitutive law with linear hardening whereas the high-fidelity model is based on an internal-state-variable representation that is influenced by the microstructural features of the material. The ATC method is applied to product-material design optimization of a multi-cell, thin-walled tube for impact energy absorption and durability. The integrated product-material optimization problem is solved using both single and multilevel approaches with results compared. © 2009 by E. Acar and M. Rais-Rohani.