基于工业CT图像的材料疲劳寿命预测

工业CT(industrial computer tomography,ICT)是在无损伤状态下得到材料断层的二维灰度图像,以图像的灰度来分辨被检断面内部裂纹的萌生、扩展情况.在分析材料的工业CT图像基础上,提出了一种疲劳寿命预测方法.首先将裂纹的萌生、扩展过程分为显微尺度细观裂纹、CT尺度裂纹和宏观裂纹3个阶段;然后采用不同的裂纹萌生、扩展标准对材料疲劳寿命进行预测;最后相加各阶段预测寿命,得到材料疲劳寿命.与疲劳累积损伤理论法、名义应力法等方法相比,该方法预测的材料疲劳寿命具有较高的精度.

Prediction of material fatigue life based on industrial CT images

A two-dimensional gray image of the material fault can be obtained without destruction by industrial computer tomography(ICT).This process is used to distinguish the seizure and the expansion of cracks within the initiation section.A fatigue life prediction method based on industrial CT images was studied.First,the crack initiation and expansion processes were divided into three phases: micro-scale thinness sight crack,CT scale crack,and macroscopic crack.Second,different crack initiation and expansion standards were adapted to calculate material fatigue life.The fatigue life of the material was the sum of the three phase's fatigue lives.Compared with other methods,such as the fatigue cumulative damage theory method and the nominal stress method,the fatigue life predicted by this method is more precise.