Sensitivity influence of initial crack characteristics on structural damage propagation based on the VB-PCE model and POD reduced order algorithm

Fatigue crack growth is normally influenced by multiple factors, including crack length, crack depth, crack angle and section radius. In this paper, an improved sensitivity surrogate model is proposed based on the VB-PCE model and POD reduction algorithm. Through the dynamic and static structural analysis and multi-order sensitivity calculations of parameters, a quantitative analysis of the multiple uncertain variables’ influence on the structural stress intensity factor is achieved. Finally, the accuracy and effectiveness of the model are verified through a typical port crane. The results demonstrate that the angle of the crack has the greatest effect on the crack parameters, while the radius of the crack interface has the least effect. The average sensitivity prediction accuracy of the influencing parameters is 93.34%. The modified sensitivity model can rapidly solve the problem of high-dimensional parameters with high efficiency and good convergence.