Novel experimental and 3D multiphysics computational framework for analyzing deformation and failure of composite laminates subjected to water blasts

The load-carrying capacity of composite structures under water-based impulsive loads is studied in relation to different materials and loading conditions. The analysis focuses on the role of fiber orientation, fiber stiffness and angle of structure obliquity relative to load direction on the deformation and failure in monolithic carbon-fiber and glass-fiber/epoxy composite plates of similar mass and thickness. Structures are subjected to impulsive loads of different intensities generated using the Underwater Shock Loading Simulator (USLS), a novel projectile-impact-based impulsive loading facility. In-situ high-speed digital imaging is used to study the deformation and failure, focusing on the effects of load intensity, failure modes and material heterogeneity. The experiments are combined with fully dynamic 3D Coupled Eulerian Lagrangian (CEL) finite element simulations accounting for the effects of fluid-structure interactions (FSI) and in-ply and inter-ply cracking and failure. It is found that the carbon-fiber laminates provide higher blast resistance, but transmit a greater fraction of the incident impulse to the supports than the glass-fiber laminates. Damage through in-ply and inter-ply cracking in the carbon-fiber laminates is ∼25% of that in the glass-fiber laminates. Higher angles of load obliquity trigger localized deformation at multiple locations, leading to more extensive in-ply damage and progressively shear-dominated rupture.