基于循环平稳的疲劳损伤检测方法

Fatigue Damage Detection Method Based on Cyclostationarity

对称循环加载是疲劳试验中常用的加载方式,该加载方式的试样振动信号具有循环平稳特性,通过采集试样疲劳过程中的振动信号并进行循环平稳性分析,提取二阶循环统计量的特征参数可描述试样损伤状态。研究目的是提取循环加载疲劳试样的循环平稳性指标,反映试样疲劳损伤累积规律。开展疲劳过程中循环加载试样振动信号的循环平稳性分析,基于提取的二阶循环统计量,建立监测变量在线描述试样损伤状态。开展疲劳试验和仿真分析,验证了该疲劳损伤检测方法的可行性。

Symmetric cyclic loading is a common loading method in fatigue test. The sample vibration signal of this loading method has the characteristics of cyclostationarity. By collecting the vibration signals during the fatigue of the sample and analyzing the cyclostationarity, the characteristic parameters of the second-order cyclostationarity can be extracted to describe the damage state of the sample.The purpose of this paper is to extract the cyclostationarity index of cyclic loading fatigue test specimen,which reflects the cumulative rule of fatigue damage.The cyclostationarity analysis of the cyclic loading sample vibration signal during the fatigue process is carried out. Based on the extracted second order cyclic statistics, the monitor variables were established to describe the damage state of the specimen.Through the fatigue test and simulation analysis, the feasibility of the fatigue damage detection method is verified.