微动磨损与微动疲劳寿命的计算与分析方法

微动损伤常见于工程中，可使紧固件松动，疲劳寿命减少和腐蚀增加，造成较大的安全隐患和经济损失．微动损伤的试验耗时耗力，还不宜损伤的直接观察，辅以计算模拟和分析十分必要．本文重点介绍微动磨损和微动疲劳寿命计算的一些方法和分析准则．其中，微动磨损计算主要介绍基于Archard公式，结合有限元计算的分析方法，以及相应的多层节点更新方法．对于微动疲劳寿命的计算和分析，主要介绍基于多轴疲劳临界面准则的判别准则，尤其是基于能量准则的Smith-Watson-Topper参数．重点介绍如何在微动条件下实现磨损与疲劳寿命的耦合求解，以及损伤的累积和破坏的判定．通过一个简单算例说明了微动磨损对其疲劳寿命可有很大的影响．

Calculation and Analysis Method of Fretting Wear and Fretting Fatigue Life

Fretting damage is a common phenomenon in engineering. It can cause fastening components loose, reduce fatigue life and enhance corrosion. Fretting experiments are generally time-consuming and difficult to conduct direct observation of damages. Computer simulation of fretting is becoming more and more popular in recent years. In this article, we shall give a review on some methods relevant for simulation and analysis of fretting wear and fretting fatigue life. For fretting wear simulation, Archard model is realized in finite element calculation together with suitable multilayer nodes update method. To estimate fretting fatigue life, multi-axial fatigue criteria are often used. Especially the so called Smith-Watson-Topper parameter can be easily implemented in simulation of fatigue crack initiation and life estimations. However, coupled calculation of fretting wear and fretting fatigue is still very time consuming, in particularly in three dimensions, although both experiments and calculations have shown clearly that fretting wear can have rather strong influence on the fatigue crack initiation and life estimation. To demonstrate this, a two dimensional example is presented. The results indicate that fatigue life estimation without considering the effect on fretting wear could be several magnitudes smaller than the life with fretting wear.