Nanoindentation characterization of Glass/Epoxy composite for viscoelastic damage interlaminar modeling

Abstract Polymer matrix composites exhibit rate dependent behavior due to viscoelastic properties of polymers. It has been assumed that the strain rate dependent mode-II delaminations in End Notched Flexure (ENF) tests are due to the viscoelastic properties of resin rich interface. In this paper a characterization procedure has been proposed within nanoindentation technique and viscoelastic properties of resin rich interface of woven E-glass/epoxy composite laminate have been characterized. Afterwards the ENF tests have been simulated by finite element method using characterized properties and developed viscoelastic cohesive zone formulation. The obtained results validate the characterization procedure for the estimation of time-dependent delamination.