Multiscale reliability analysis of a composite stiffened panel

A method for performing reliability analysis of a composite stiffened panel subjected to axial compression using the finite element method is discussed. Three-dimensional shell and brick element models are utilized for baseline response prediction, and comparison with experimental results. Owing to the multiscale nature of composite materials, microscale and macroscale design parameters are identified for the panel. The microscale parameters consist of fiber⧹⧹matrix properties and the volume fraction. The macroscale parameters consist of structural dimensions, layup definition, and an imperfection scale factor. The fiber and matrix properties are estimated utilizing a micromechanics model in conjunction with an optimization method. Thereafter, parameterized finite element models are used to generate an approximation model. Utilizing the Monte Carlo method, design parameters were subject to variation and the variation in response was predicted using the approximation model along with the probability of failure measured against experimental results and baseline finite element responses.