Compliant Mechanism Design Using the Hybrid Cellular Automaton Method

Abstract

This paper presents a new methodology for obtaining optimal topologies in continuum structures for compliant mechanism design. This non-gradient approach uses the Hybrid Cellular Automaton (HCA) method. The HCA method is a biologically inspired algorithm that has been used for structural topology optimization. HCA divides the design domain into a lattice of cellular automata (CAs). Locally, each CA is able to modify a continuum structural design variable based on the energy in its neighborhood. A global structural analysis using a flnite element method is used to obtain the information for each iteration. The local change in the design variable is determined by a local design rule. In previous applications to structural optimization, these local rules were implemented to achieve uniform strain energy density throughout the structural when loaded. In the application to compliant mechanisms, the structure must exhibit both ∞exibility and rigidity are required. The mechanism must be able to transfer a force from an input location to the output location while being able to withstand the input force. Therefore a multi-objective formulation is considered so that a uniform distribution of a combination of the two objectives is achieved. The algorithm has shown to be e‐cient as well as resulting in topologies that distribute compliance in uniform manner in that hinges are avoided. In this paper, we will illustrate the use of HCA in 2D and 3D compliant mechanism design using a static nonlinear analysis allowing for large deformations.