Finite Element Based Method to Predict Gas Permeability in Cross-ply Laminates

Abstract

A finite-element based method is developed to predict gas permeability in cross-ply laminates. Based on Poiseuille's Law and Darcy's Law, the gas permeability is presented in terms of crack densities, microcrack opening displacements and an experimentally determined constant. The crack densities in each ply are predicted using finite element analysis based on energy concept of micro-fracture mechanics. The microcrack opening displacement of the representative volume element in cross-ply laminate is computed using three-dimensional finite element analysis. The normalized gas permeability in three laminates with different lay-ups are predicted and compared using the current model. Finally, a permeability-related material constant is quantified using the experimental results available in the literature.

A new device to measure permeability evolution under pressure loading: Application to CFRP pipes

“…crack density and delamination length, from the loading history and the material properties [4,[6][7][8][9][10][11][12]. Damage state and current loading can then be used as input for crack opening displacement prediction [10,11,13], and also for permeability prediction [11][12][13][14][15][16][17]. Yet the prediction of crack connections managed by crack length and distribution remains a core issue and still requires experimental data on the link between load, number of leak paths and permeability.…”