Researches On Topology Optimization Designs Of Compliant Mechanisms Based On Adaptive Constraints

The research on compliant mechanism designs based on topology optimization methods is a hot research direction in the field of compliant mechanism researches.There still is a single hinge connecting problem in the topological configuration of optimization results obtained by the existed topology optimization methods.The single hinge connecting problem not only leads to the difficulty degree increases of compliant mechanism manufactures,but also leads to a compliant mechanism with worse performaces and functions.For the single hinge connecting problem in the topology optimization of compliant mechanisms,it is of important theoretical significance and engineering application value to investigate the topology optimization design of compliant mechanisms based on adaptive constraint technology.First of all,based on the conventional SIMP method,another SIMP method,based on a feasible domain adjustment,namely a FDA-SIMP method,is bulit,and a comprehensive compliance function is constructed to represent a comprehensive stiffness characteristic of inputs and outputs of a compliant mechanism.Combining with several numerical simulation examples,researches on topology configurations of compliant mechanisms obtained by the above two methods and their characteristics in the process of topology optimization,are completed.And the mentioned-above design results and the cause of the single hinge phenomenon are analyzed.It is found from a lot of simulation examples that the compliant mechanism not only should have the flexibility to satisfy prescribed functional requirements,but also should have the rigidity to support the external load;and a large change of the comprehensive compliance function between two successive iterative steps may lead to the emergence of a single hinge phenomenon.In order to solve the single hinge connecting problem,a compliant mechanism optimization model with adaptive constraints of a comprehensive compliance function is constructed.In this paper,a new compliant mechanism topology optimization method based on the adaptive constraints is proposed,being integrated with a varied volume constraint scheme and a smooth dual algorithm,and a large number of numerical simulation examples are given.Then,the proposed method is extended to topology optimization designs of multi-input and multi-output(referred to as MIMO)compliant mechanisms.The numerical examples results obtained show that the proposed method not only may solve the single hinge connecting problem,but also get a clear optimal structural topology;the proposed research work in this thesis is of important theoretical significance and engineering application value.