基于有限元的平面微弹簧疲劳性能研究

摘要平面微弹簧作为微纳加工系统的一种重要器件，它可以起到向MEMS系统提供弹性驱动力与传递弹性势能的作用，亦可应用在微传感器领域。本文利用有限元模拟的研究方法，构建了平面微弹簧的几何模型与有限元模型，研究了弹簧线宽，厚度及常见裂纹对微型弹簧疲劳的力学性能起到的影响。模拟实验还制备了应力应变云图以直观描述弹簧内部的受力情况。研究表明：理想情况下铝青铜微弹簧的疲劳寿命理论上可以达到上万次，远高于目前制备的平面微弹簧的疲劳寿命测试值，为平面微弹簧疲劳性能的提升提供了理论支撑。有限元模拟结果表明了平面微弹簧的线宽、厚度与疲劳寿命成正相关关系，在微机电系统允许范围内适当增加弹簧的线宽与厚度可大幅度提升其疲劳寿命而不影响器件的性能以及空间占用。通过应力应变分布图我们知道，在弹簧的拐角处容易出现应力集中现象，极大降低弹簧的使用寿命，因此为提高弹簧的机械性能，应保证弹簧的光滑性。同时，我们发现，裂纹缺陷的存在可使疲劳寿命严重下降，因此，获得好的弹簧必须要降低弹簧表面和内部的缺陷。42466

关键词平面微弹簧有限元模拟疲劳（力学）铝青铜合金

毕业论文网设计说明书外文摘要

Title The study of the fatigue function of micro-spring by finite element simulation

Abstract

Planar micro-spring , as an important device of micro processing, provide the MEMS system with elastic driving force and transfer elastic potential energy. It can also be used in the field of micro sensors. In this paper, the geometry model of planar micro-spring has been structured. The influence of micro spring’s fatigue property, caused by the common flaws and different width and thickness of micro-spring, is be used to studied by the finite element simulation. The stress and strain distribution map is studied to describe the mechanics situation inside the spring. Research shows: The fatigue lifetime aluminum bronze can acquired the fatigue lifetime which be more than ten thousand time in ideal situation, it’s more than the fatigue lifetime acquired by text. It’s provide the academic support for the prospect of the improving of micro-spring. The simulation results show that the line width, thickness and fatigue life of the planar micro spring are positively correlated, and the increasing of the width and thickness of the spring can increase the fatigue life of the spring. It’s described by stress and strain distribution diagram that the stress concentration phenomenon is occurred at the corner of the spring. The existence of flaw inside the spring could reduce the fatigue life severely. Therefore, is necessary to reduce the defects to obtain a useful micro-spring.

Keywords Planar micro-spring Finite element simulation Fatigue property Aluminum bronze alloy

1.绪论 1

1.1平面微弹簧 1

1.1.1平面微弹簧概述 1

1.1.2平面微弹簧的制备方法 1

1.2有限元分析法介绍 5

1.2.1有限元分析方法概述 5

1.2.2有限元的分析过程 6

1.2.3有限元分析方法的优点 7

1.3本课题的研究意义及主要内容 8

2.有限元模型及模拟实验方案基于有限元的平面微弹簧疲劳性能研究:http://www.youerw.com/cailiao/lunwen_42935.html