Optimal Synthesis of Topology for Compliant Mechanisms

Abstract

Abstract The aim of the present work is disclosing a model suitable to provide a new tool for the synthesis of mechanisms and structures. Firstly, a framework will be introduced for the representation of a particular class of mechanisms: compliant mechanisms. For this purpose, the constitutive elements and the relations between the elements are organized in a taxonomy, similar to the ones used for the definition of ontologies. Ontologies have been taken as inspiration for the construction of the general schema for two main reasons: the first one is the need of consistency in the physical models, in order to obtain reliable results. The second reason is that one of the main features of ontologies is modularity, which means that they may be reused, and implemented for the creation of widest classifications. In the proposed framework, mechanisms result from the combination of the constitutive elements, according to a certain topology. The topologies are generated taking in account the defined feasible relations between elements. Once the mechanisms are defined, their behavior, in terms of mechanical response, is calculated and implemented in the schema as well. Finally, a classification of the evaluated mechanisms is provided, correlating the mechanical behavior of the mechanisms to the topological arrangement of their elements, or, in other words, their geometry. This classification may be synthetized in a table which may be query setting the mechanical response (set of deformation allowed or denied as response of a set of generalized forces). The result of the query is the indication of the topology of the mechanism that fits the mechanical response best. The proposed table is a design tool actually, suggesting the constructive form to the designer starting from a functional requirement. Moreover, considering the table of topologies and the physical model with which it was generated, they constitute a synthesis tool for that class of mechanisms, and, ultimately, a topology, and size optimization tool.