Effect of transverse cracking on stiffness reduction of hygrothermal aged cross-ply laminates

An analytical model based on the notion of the stress perturbation function is developed and applied to study the effect of multiple cracks in aged cross-ply laminates on the stiffness of a laminated composite. The material properties of the composite are affected by the variation of temperature and moisture, and are based on a micro-mechanical model of laminates. This hygrothermal effect is taken into account to assess the changes in the longitudinal modulus due to transverse cracking. The obtained results represent well the dependence of the degradation of elastic properties on the cracks density and hygrothermal conditions. Through this theoretical study, we hope to contribute to the understanding of damage of aged composite materials.