Thermoelastic fracture behavior of bimodular functionally graded skin-stiffener composite panel with embedded inter-laminar delamination

In the present work strain energy release rate as a fracture parameter has been used to evaluate the skin-stiffener debonding in stiffened composite panel with functionally graded (FG) bimodular material property under thermo-mechanical coupled field. The influence of ply lay-up and interaction of residual thermal stresses on the skin-stiffener has been investigated. Stress-dependent elasticity problem of bimodular stiffened panel made up of laminated fiber reinforced polymeric composite is carried out using finite element analysis under various bimodular ratios. The numerical result in terms of compressive load as a function of applied displacement has been compared to the existing literature data to assess the effectiveness of the implemented methodology. Variation of energy release rate along the interface delamination front has been plotted for both mechanical and thermo-mechanical coupled loading with modulus ratio R varying from 1 (unimodular) to 5. Asymmetric variation of energy release rate along the interfacial front has been observed for the bimodular stiffened composite panel.