A Residual Strength Prediction Methodology for Composite Laminates With Surface Damage Under Tensile Loading

摘要

A fracture mechanics methodology is presented to evaluate failure of composite laminates with surface damage under tensile loading. The methodology is appropriate for cuts and gouges, which can be represented as partial thickness cracks in the laminate. The partial thickness cracks are modeled as through-thickness cracks loaded by springs to represent the effect of the unfailed material under the cut plies. An equation for the spring stiffness is presented and used to calculate stress intensity factors for the damaged laminate. These results are combined with material fracture toughness data and net-section strength checks to obtain a residual strength prediction. The methodology predicts an available set of experimental strength results for partial thickness cuts in glass/epoxy laminates.