摘要
基于损伤力学理论建立金属疲劳裂纹损伤模型,结合有限元法预估疲劳微裂纹萌生及扩展全寿命。引入附加载荷法,实现了对刚度矩阵的连续计算,应用Matlab编程计算,通过对单个单元的损伤计算,得到了单元从无损到破坏过程中等效应力的变化,进而给出疲劳裂纹损伤模型,并对不同规格金属试件的疲劳寿命预估。将计算结果与试验结果进行对比,得到的相对误差在接受范围内,验证了该模型的准确性,对于研究金属试件微观损伤以及疲劳寿命预估具有重要的参考意义。
Based on theory of damage mechanics,the damage model of metal fatigue crack is constructed and combining the model with finite element method the whole life of crack initiation and crack propagation is predicted. The stiffness matrix is continuously calculated by introducing the calculation of additionalload.The calculating program is designed in Matlab and the calculation flow diagram has been showed in thispaper. Then through the calculation of a single cell,the changing process of equivalent stress is showed with the cell from undamaged state to completely damaged state and the damage model of fatigue crack is given.It used the model to calculate the fatigue life of different metal test specimen and compared calculation results and experimental results.The error is acceptable which verified the correctness of this method and ithas important reference significance for the study of the microscopic damage and fatigue life prediction of metal material.
出处
《机械设计与制造》
北大核心
2018年第3期50-52,56,共4页
Machinery Design & Manufacture
基金
国防技术基础项目(Z092012B001)
关键词
疲劳寿命
损伤力学
金属裂纹
有限元法
Fatigue Life
Damage Mechanics
Metal Crack
Finite Element Method
