Experimental/numerical characterization of hygrothermal ageing in glass/epoxy composites

In this work, a combined experimental/numerical approach is used to investigate the effect of water ingression in glass/epoxy composite specimens. Interlaminar shear (ILS) specimens were immersed at 50◦C for multiple durations and tested. Re-dried specimens were also tested. Significant strength degradation of up to 50% was found for wet specimens, while dried ones showed an irreversible decrease in strength of approximately 9%. The diffusion phenomenon was also investigated numerically in a multiscale /multiphysics framework. At the microscale, an RVE combining linear-elastic fibres, elasto-plastic resin with damage and cohesive interfaces was used. At the macroscale, a classic stress equilibrium analysis is coupled with a Fickian diffusion model, and an independent micromodel is run at each macroscopic integration point. The model was used to simulate diffusion in a short-beam specimen and regions of plastic deformation, interface failures and softening bands in the resin were identified.