基于失效路径的含裂纹起重机寿命预测

四川大学制造科学与工程学院,成都 610065

起重机械; 冶金起重机; 疲劳裂纹; 裂纹扩展; 失效速率; 曲线拟合; 剩余寿命

Residual life prediction of crane with crack based on the defect failure path
Huang Jiang and Long Wei

Huang Jiang and Long WeiCollege of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065, P.R.China

lifting machine; metallurgical crane; fatigue crack; crack extension; failure rate; curve fitting; residual life

DOI: 10.3724/SP.J.1249.2015.03245

备注

针对桥式冶金起重机金属结构裂纹缺陷失效临界尺寸值难以确定的问题,通过交变载荷加载试验,对裂纹缺陷的失效路径和失效速率进行仿真,得到其真实的失效离散轨迹.利用Matlab进行曲线拟合,建立失效速率与裂纹尺寸之间的函数关系式,采用数值积分法计算缺陷剩余寿命,得到速率拐点处裂纹的几何参数,即标准临界尺寸值,为Paris迭代法评估金属结构疲劳裂纹失效提供了理论依据.

It is quite difficult to determine the exact critical value of metal structures in bridge metallurgical cranes with fatigue crack failures. This paper simulates the defect failure paths and rates of metal structures by performing cyclic loading tests and obtains a real trajectory of assessing points. A function between failure rates and crack size is established by using Matlab software, and the residual life of defects is calculated by numerical integration. Finally, an accurate mutation point, also called a “standard critical size value”, can be calculated from the simulation map. Thus, this work provides a more scientific and precise theoretical basis of the Paris iterative method for assessing the fatigue crack failures of metal structures.

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