摘要
近年来，柔顺机构逐渐被人们所知，成为许多学者关注的焦点。柔顺机构摒弃了传统刚性机构的缺点，具有许多传统刚性机构无法比拟的优点，诸如：结构简单，装配难度小，节省材料，加工成本和人力成本低、机构寿命高等。正因为柔顺机构有以上优点，柔顺机构被广泛应用于各行各业。而连续体结构拓扑优化是柔顺机构设计方法中的研究热点和难点。
本文对ICM方法进行了研究，系统研究了ICM方法的基础概念，包括独立拓扑优化变量的建立，过滤函数和磨光函数以及参数的映射和反映射。根据ICM方法的过滤函数概念和变密度法建立了基于位移的连续体结构拓扑优化模型，并研究了序列二次规划算法、优化准则法和移动渐近线系列方法求解优化模型时的效率。
研究了基于变密度法的SIMP方法。对比过滤函数和SIMP插值模型相同点，将过滤函数作为惩罚函数，以体积比为约束函数，分别以最大输出位移和最大机械性能为目标函数，建立柔顺机构拓扑优化模型。以位移反向器为例，应用优化准则法和移动渐近线法求解，对比求解效率和求解结果，对过滤函数参数进行了选取，验证了过滤函数作为惩罚函数的可行性。针对SIMP方法和Sigmoid方法的缺点，对Sigmoid方法进行了改进。
本文基于Msc.Patran&Nastran建立了柔顺机构参数化建模分析的二次开发平台，利用Msc.Patran的二次开发语言PCL语言，建立了参数化建模分析模块，简化了建模和分析流程，方便操作。根据Msc.Patran的模型及分析结果和Isight优化软件，建立了柔顺夹钳的拓扑优化流程框图。使用建立的优化平台进行位移反向器结构设计，验证了文中方法的正确性，对柔顺机构设计具有借鉴意义。
关键词：柔顺机构，拓扑优化，惩罚函数，PCL二次开发
Abstract
In recent years, the compliant mechanism is gradually being known, and has become the focus of many scholars. The compliant mechanism abandons the shortcomings of the traditional rigid structure and has many advantages over traditional rigid structure, such as: simple structure, low assembly difficulty, material saving, low processing cost and labor cost, and high lifespan, thus compliant mechanism is widely used in many fields. Topology optimization of continuum structure is a hotspot and difficulty in the design of compliant structure.
This paper studies the ICM method and systematically studies the basic concepts of the ICM method, including the establishment of independent topology optimization variables, filter functions and smoothing functions, and the mapping and inverse mapping of parameters. According to the concept of filter function of ICM method and variable density method, a topology optimization model of displacement-based continuum structure is established. The efficiency and structure of sequential quadratic programming algorithm, optimization criteria method and moving asymptotic series method to solve the optimization model are studied.
Based on the variable density method, the traditional SIMP method is studied, and different filter functions were applied to the variable density method. With the volume ratio as the constraint function, a compliant mechanism topology optimization model was established using the maximum output displacement and the maximum mechanical performance as objective functions. Taking the displacement inverter as an example, the optimization criteria method and the moving asymptotic method are applied to solve the problem. The efficiency of the solution and the result of the solution are compared.
Based on Msc.Patran&Nastran, this paper establishes a secondary development platform for compliant mechanisms, and uses the secondary development language PCL language of Msc.Patran to establish a parametric modeling analysis module, which simplifies the modeling process and facilitates operation. Then based on the model and analysis results and the Isight optimization software, a topology optimization flow diagram of the compliant gripper was established.
Key words: filter function, topology optimization, compliant mechanism, PCL language