Numerical probabilistic approach to sensitivity analysis in a fatigue delamination problem of a two layer composite

摘要

Fatigue delamination is the primary mode of failure of composite laminates subjected to cyclic loads. Several parameters can affect the fatigue delamination growth in laminates – that includes e.g. constituent material properties and/or composite shape. Knowledge about effects of those parameters can lead to a better understanding of the fatigue delamination behavior and can also pinpoint directions for optimum composite design. Those effects can be elucidated by undertaking appropriate sensitivity analysis. Hence, a probabilistic approach to sensitivity analysis is proposed in this work to study the effects of composite parameters in a fatigue delamination problem of a two-layer composite. This approach combines together a fatigue delamination model, Monte Carlo simulations and the finite element method (FEM). As a result, probabilistic sensitivities are obtained in the form of correlation coefficients and also as trend-line gradients. Accuracy and efficacy of the approach is evaluated based on two numerical examples. The current approach is found to be insensitive to the parameter standard deviation and number of sampling points. Moreover, the current approach can be used irrespectively from the type of the boundary value problem (linear or non-linear) provided that the problem is solvable by the numerical method such as the FEM.