Hybrid Cellular Automata: a biologically-inspired structural optimization technique

Abstract

In this investigation the hybrid cellular automaton (HCA) method for structural synthesis is extended to facilitate simultaneous topology and shape optimization. The HCA methodology has been developed for application to continuum structures. The development of this methodology has been inspired by the biological process of bone remodeling. In bone remodeling, only those elements located on the surface of the mineralized structure can be modified. In the HCA methodology implemented in this research only surface elements are allowed to change density during the structural synthesis process. The HCA method combines local design rules based on the cellular automaton paradigm and finite element analysis. Closed-loop control is used to modify the mass distribution on the internal and external surfaces of the design domain to find an optimum structure. The local control maintains a balance between mass and rigidity. The new methodology effectively combines elements of topology optimization and shape optimization into a single tool. Three classes of test problems are used to illustrate the method’s efficacy.