多场耦合下功能梯度微机电系统非线性结构力学性能研究

This study focuses on the nonlinear structural mechanics property of the Micro-Electro-Mechanical Systems (MEMS) based on functionally graded materials (FGMs). The main contents include the following aspects: considering the coupling effect of the mechanical field, electric field and temperature field, build the thermo-mechanical-electro coupling nonlinear model of the functionally graded MEMS beam and plate; investigate the instability of the functionally graded MEMS beam and plate, make comprehensive analysis about the influence of the nonlinear electric field force, change of temperature and gradient parameters of FGMs on the buckling, thermal buckling and pull-in instability; analyze the nonlinear vibration and dynamic response of MEMS beam and plate; simulate the nonlinear structural mechanics property by multi-field modeling and simulation software; experimental research. The research aims to investigate the effect of the nonlinear electric field force, change of temperature and gradient parameters of FGMs on the nonlinear structural mechanics property of MEMS. This project studies how to improve the performance of the MEMS devices, especially meet the request of heat resistance, through the critical parameters adjustment. It aims to provide a new design idea for the design and optimization of MEMS.

本项目研究将主要集中于基于功能梯度材料的微机电系统(Micro-Electro-Mechanical Systems，MEMS)非线性结构力学性能问题，主要内容包括：考虑机械场、电场及温度场的耦合效应，建立基于功能梯度材料的MEMS梁、板结构热-机-电耦合非线性力学模型；研究功能梯度MEMS梁、板结构失稳特性，综合分析非线性电场力、温度变化及材料梯度参数对屈曲、热屈曲及吸合失稳特性的影响规律；研究功能梯度MEMS梁、板结构非线性振动及动力响应特性；对功能梯度材料MEMS梁、板结构非线性力学性能进行多物理场模拟和实验研究。主要目的是：综合考察非线性电场力、温度变化及功能梯度材料梯度参数对MEMS非线性结构力学性能的影响，研究如何通过调整系统关键参数提高MEMS器件工作性能，尤其满足耐热性能的要求, 为MEMS系统设计与优化提供一种新的设计思路。

本课题采取理论分析和数值模拟相结合的思路，在分析功能梯度MEMS梁、板结构力学特性的基础上，建立了能反映微机电系统热-机-电耦合工作模式的非线性力学模型，对功能梯度MEMS梁、板结构屈曲、热屈曲、吸合失稳、非线性振动及动力响应进行分析。考察材料物性参数、结构尺寸参数、外加载荷等的影响，综合分析了功能梯度材料梯度参数及其温度依赖性、微梁细长比、初始间隙参数、固定极板形状参数、外加电压、分子间作用力、轴向残余应力、温度变化等对功能梯度MEMS微梁、微板力学特性的影响。完成了测试实验平台的设计与实验方案设计，申请了相关专利。研究结果表明可以通过调整系统关键参数来提高MEMS器件的工作性能。本项目研究成果对针对性设计新型MEMS器件具有重要理论意义，同时可以促进多场耦合力学的发展。