关键词: 非线性预测滤波, 疲劳裂纹扩展预测, Paris公式, Lamb波

Abstract: A fatigue crack growth prediction method was proposed based on NPF algorithm, aiming at solving the problems that traditional Paris fatigue crack growth model had low accuracy and could not take the influences of various uncertain factors in the crack growth processes into consideration. State space equations were used to characterize crack growth processes based on Paris formula. Observation space equations were established using monitoring technology based on Lamb waves.The real-time observation information was used to modify the predicted values of the model. Finally, the effectiveness of the method herein was verified by the fatigue crack growth experiments of Q235 steel specimens. Experimental results show that the NPF algorithm may effectively correct prediction errors of Paris formula in fatigue crack growth prediction. The prediction accuracy is better than that of the extended Kalman filter and particle filter(PF) algorithms, and the algorithm efficiency is significantly better than that of PF algorithm.

Key words:  , nonlinear predictive filtering(NPF), fatigue crack growth prediction, Paris formula, Lamb waves