基于剩余强度退化规律的疲劳损伤非线性演化模型  

NON-LINEAR MODEL OF FATIGUE DAMAGE BASED ON THE RESIDUAL STRENGTH DEGRADATION LAW

作　　者：苏志霄[1] 刘宏昭[2] 王建平[2] 曾惟庆 

机构地区：[1]清华大学工程力学系,北京100084 [2]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《机械强度》2000年第3期238-240,共3页Journal of Mechanical Strength

基　　金：国家自然科学基金!(59475007);教委留学回国人员基金资助项目

摘　　要：通过对正火４５钢的试验数据分析，提出了一个反映剩余强度退化的对数表达式，给出对称恒幅应力循环下疲劳损伤的定义与表达式。该表达式能够反映损伤演化的非线性特性。进一步分析了随机应力循环下结构的疲劳损伤，导出损伤演化的递推公式，并结合大量的计算给出结构在应力块重复循环下疲劳寿命估算的一个近似方法。Firstly, according to analyze the fatigue test result of the normalized carbon steel, a logarithmic expression is developed to describe residual strength degradation process, the definition and expression of fatigue damage under symmetrical she with constant amplitude are also given, and the expression 'can explain the non-linear property of fatigue damage. Secondly, the fatigue damage of structures under random stress is analyzed, ed an iterative formula to describe the fatigUe damage process is deduced. At last, an approximate method for evaluate fatigue life of structures under repeat random stress block is presented through a lot of calculation examples.

关 键 词：疲劳损伤 强度退化 随机应力 非线性演化模型 

分 类 号：O346.2[理学—固体力学] O346.5[理学—力学]