基于自相关函数法的疲劳断口图像条带周期测量

Fatigue period measurement of fracture images based on autocorrelation function

疲劳条带是疲劳断口典型的微观特征,其条带周期是疲劳断裂定量分析中的重要参数,对于金属疲劳的自动故障诊断具有重要意义。本文首先分析了金属疲劳的断裂机理、条带的周期特性,建立了疲劳条带周期计算的三角关系模型,最后提出了基于自相关函数法的疲劳条带周期测量方法,并与人工方法进行性能对比。实际疲劳条带周期测量结果表明:基于统计的自相关函数法不但可以减少人为因素的干扰,提高测量精度,而且运算效率高,疲劳条带周期测量的正确率可达88.54%,能满足工程实际的需要。

Fatigue striation is the typical microscopic characteristics of fatigue fracture,and the period of fatigue striation is important to fatigue quantitative analysis and metal fracture automatic diagnose.In this paper,the metal fatigue fracture mechanism and strip periodic characteristics were analyzed.Then a triangular mathematical model was established.Finally,a statistic autocorrelation function method for striation measurement was proposed.The experiment results indicated that the statistic autocorrelation function method can reduce artificial factors interference,increase the measurement precision,and improve operation efficiency.The fatigue striation period measurement accuracy reaches 88.54%,which can satisfy the demand of practical engineering.