描述弹塑性材料损伤演变行为的3种计算方法的研究与应用

摘要

By means of bidirectional combined coordinate system, three kinds of calculation methods are proposed with respect to the damage-evolving rate and the life of elastic-plastic material, which include the single-parameter method, the ratio-method and the multiplication-method. In this work a lot of new calculation equations are given; a new concept on the all-around material constant is provided,which has functional relations with each of the typical material parameters: the fatigue strength coefficient σ'f, the fatigue strength exponent b'1, the fatigue ductility coefficient ε'l' the fatigue ductility exponent c'1, the average stress,the average strain, critical loading time and so on. In addition, an example of a car part is given, and some comparisons of calculation results are made. The calculation methods will have practical significance in avoiding the unnecessary fatigue tests, saving time, manpower and capital, as well as providing the convenience for engineering applications in a certain degree.%借助于双向组合坐标系,就弹塑性材料的损伤演变速率和寿命提出了3种计算方法.它包括:单参数法、比值法、乘积法,同时本文给出了许多新的计算方程,还提供了一个同各个常用材料参数有着函数关系的综合性材料常数的新概念.这些常用参数有:疲劳强度系数σ'f、疲劳强度指数b'1、疲劳延性系数ε'f、疲劳延性指数c'1、平均应力、平均应变和临界加载时间等等.用汽车的一个零件做了实例计算,并对计算结果进行了一些比较.预计这些计算方法对避免过多的疲劳试验,对节省疲劳试验的时间、人力和资金,对方便工程应用在某种程度上将有着实际意义.