应变疲劳寿命的强度稳定综合理论法研究 - 哈尔滨工程大学学报.PDF

应变疲劳寿命的强度稳定综合理论法研究 , 熊志鑫 佟福山 （哈尔滨工程大学 船舶工程学院，黑龙江 哈尔滨150001） 摘 要： . 应变疲劳分析是解决结构失效问题的重点研究内容之一 运用强度稳定综合理论及方法将应变疲劳寿命转化为切线 . 模量因子的表达，通过分析转化过程中的无量纲曲线，发现一些材料间的固有规律 以切线模量因子为“桥梁”，将循环应力 应变曲线中的应力作为裂纹扩展时的临界应力，对应该应力的应变值当作疲劳试验的控制应变幅值，则对应的裂纹长度就是 应变疲劳寿命的折算裂纹长度；通过切线模量因子建立的衍生比例定律和应力疲劳寿命的建模方法可以得到寿命应变关系的 . GM 5%. 预测模型 这一模型与灰色系统理论的 模型具有相同的数学表达，并通过实验数据验证该模型的误差小于 关键词： 应变疲劳寿命；应力应变曲线；切线模量因子；折算裂纹长度；微分方程 中图分类号：O346.2 文献标识码：A 文章编号：1006-7043 (2010) xx-xxxx-x Strain Fatigue Life Analysis Based on the Combined Theory of Strength and Stability XIONG Zhi-xin , TONG Fu-shan （College of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001,China） Abstract Abstract AAbbssttrraacctt：Strain fatigue analysis is one of the important researches to solve the failure of engineering structures. An expression between fatigue life and tangent modulus factor is established by using Combined Theory of Strength and Stability. Among this process, the fatigue performance test curves are analyzed and used to find some inherent rules of material. While considering stress as critical stress, the strain corresponding to the stress value can be chosen as control strain breadth to fatigue experiment. According to fatigue performance curves and concerned parameters, the relationship between fatigue life and crack half length is obtained, which is equivalent crack length of fatigue life. A differential model is established by using Proportional Limit Law and the function of stress fatigue life. This model has