无扩口管路连接件疲劳寿命预估的损伤力学-有限元法

 以损伤热力学为基础，构建分式形式的损伤演化方程。针对管路连接件等轴对称形式的构件，引入等效应力和等效应变。根据损伤力学守恒积分原理，得到恒幅重复载荷下应力与寿命关系的级数表达式，根据标准件疲劳试验结果拟合得到损伤演化方程中的材质参数。利用APDL语言编程对ANSYS软件进行了开发，使得借助ANSYS软件的损伤力学-有限元数值解法成为可能。利用该方法预估了TC6钛合金标准件疲劳裂纹萌生寿命，其结果与试验数据吻合。进一步，预估了管路连接件裂纹萌生寿命，预测了裂纹扩展路径并预估了疲劳裂纹扩展寿命。本文为采用损伤力学方法来预估构件的疲劳寿命提供了一种可行的方法。

Damage Mechanics-Finite Element Method for Fatigue Life Prediction of Flare-free Pipeline Connection Assemblies

In this article,based on irreversible thermodynamics,a damage evolution equation of fractional form is constructed.Furthermore,effective strain and effective stress are introduced into the study of pipeline connection assemblies under the condition of axial symmetry.By means of the theory of conservative integral,the series of power function is derived to express the relation between the stress and fatigue life under repeated loading with constant amplitude.The material parameters are obtained by the result...