On Profile Extraction And Shape Optimization Of Planar Path Generating Compliant Mechanisms

Compliant mechanism is one of the hottest research subjects in the mechanism field in recent years. Because of no clearance, no wearing, not need to assemble or any other advantages which the rigid machines do not have, compliant mechanisms are broadly used in aviation, MEMS, biomedicine and so on. Compliant mechanisms are defined as mechanisms that gain some or all of their motion due to the relative flexibility of part or all of their members. Therefore, the design method of compliant mechanism is greatly different from that of traditional rigid-body mechanism and the design methodology for compliant mechanism has not been established systemically till now. Concerned with such problem, this paper develops a synthetically method on the design of planar path-generating compliant mechanisms, with the support of the the projects from the National Natural Science Foundation of China and the National High-Tec Research and Development Plan of China .This thesis investigates the profile extraction and shape optimization on the result of topology optimization of planar compliant mechanisms. The main context includes the following work: (1) summarizing and analyzing the recent research status, some harvest and unsolved problems; (2) analyzing the conceptual design of planar path-generating compliant mechanisms and its mathematical model and tools; (3) Modifying the method of density contour as the method of profile extraction, and developing a method to optimize the density function in the profile extraction according to the requirement of the design of compliant mechanism; (4) developing a method to abstract the compliant mechanism into a form of links and joints by using the principle of connectivity on topology; (5) developing a method of shape optimization of planar path-generating compliant mechanisms, by representing the profile of the abstracted compliant mechanism as simple curves such as straight lines and arcs, establishing the models of the size optimization of the parameters of these curves, so that the compliant mechanism has a machinable shape; (6) At last, proving the feasibleness and effectiveness of the design method by making simulation design and validating it in FEA software.The research results in this thesis show that the developed method succeeds to synthesize of topology optimization and shape optimization for planar compliant mechanisms. And compliant mechanisms will have a greatly foreground in the MEMS.