Thermoelastic analysis of the asymmetries of interfacial embedded delamination characteristics in laminated FRP composites

This paper presents two sets of full three-dimensional thermoelastic finite element analyses of superimposed thermo-mechanically loaded FRP composite laminates with embedded interfacial elliptical delaminations, emphasizing the influence of residual thermal stresses and material anisotropy on the delamination fracture behavior characteristics. Modified crack closure integral (MCCI) methods based on the concepts of linear elastic fracture mechanics (LEFM) have been used as a meaningful tool to calculate the individual modes of strain energy release rates from the thermoelastic stress and displacement fields due to a combined thermal and a quasi-static impact loading. Residual stresses developed due to the thermoelastic anisotropy of the laminae are found to strongly influence the delamination onset and propagation characteristics, which have been reflected by the asymmetries in the nature of energy release rate plots and their significant variation along the delamination front.