疲劳裂纹扩展随机过程相关参数的估计

对数正态随机过程模型是可靠性与损伤容限分析中常用的裂纹扩展随机模型.在裂纹扩展对数正态随机过程模型的基础上,建立了由试验数据估计一般平稳正态随机过程相关参数的方法.应用这种方法可以直接由试验数据估计随机过程的相关参数.同时,给出了用Monte-Carlo方法估算置信区间的方法.最后,给出了用具体试验数据,这组试验数据共有237个数据点,估计随机过程相关参数的算例.

Correlative Parameter Estimated Method in Random Process of Fatigue Crack Propagation

Lognormal random process model of fatigue crack propagation is usually used in the reliability and damage tolerance analysis.Basing on the model, a new method of evaluating the auto correlative parameter in usual stationary normal random process by the experimental data is established.By using this method, the value of the correlative parameter can be evaluated directly on the basis of the experimental data.At the same time, the confidence interval of the parameters is obtained by using Monte-Carlo method.At the end of the paper, a numerical example is given.In this example, a group experimental data of the specimens with fastening holes under pseudorandom spectrum loading, that obtained 237 data points, is used to determine the value of this correlative parameter.