Stochastic J-integral Of Laminated CompositesBased On An Efficient Finite Element AnalysisMethodology

Abstract

Laminated composites with spatial and sample-to-sample stochastic variations in material properties are considered in the present paper. The fracture behavior of such laminated composites is quantified through the J-Integral and the variabilities in the J-Integral. An efficient stochastic finite element analysis methodology is formulated and applied for this purpose. The capability of the more conventional parameters such as the stress intensity factor and the strain energy release rate in precisely quantifying and characterizing the stochastic fracture behavior of laminated composites is evaluated. The displacement extrapolation method (DEM) and the energy release rate method (ERRM) are employed for this purpose. The analytical probability distributions of fracture parameters are determined based on the Maximum Entropy Method (MEM). The effects of the finite width of the laminate and the relative size of the crack with respect to the finite plate width are quantified. The optimum number of simulations in the stochastic analysis is determined considering each fracture parameter. A cross-ply laminate is employed as a vehicle for demonstrating and illustrating the formulation and applications developed in the present work.