Topology Optimization for Synthesizing Extrusion Based Nonlinear Transient Designs

Concept designs synthesized using conventional topology optimization methods are typically not easily manufacturaed, in that multiple finishing processes are required to construct the component. A manufacturing technique that requires only minimal effort is extrusion. Extrusion is a manufacturing process used to create objects of a fixed cross-sectional profile. Extrusion often minimizes the need for secondary machining, although not necessarily of the same dimensional accuracy as machined parts. The result of using this process is lower costs for the manufacture of the final product. In this paper, a non-gradient hybrid cellular automaton (HCA) algorithm is developed to synthesize constant cross section structures that are subjected to nonlinear transient loading. Examples are presented to demonstrate the efficiency of the proposed methodology in synthesizing these structures. The methodology is first demonstrated for elastic-static modeling. The novelty of the proposed method is the ability to generate constant cross section topologies for plastic-dynamic problems since the issue of complex gradients can be avoided using the HCA method.