Depth of penetration experiments of S-2 glass/epoxy composites: A new Experimental Methodology in determining the rate dependent dynamic crush strength of composites

Abstract

Depth of Penetration (DoP) experiments have been conducted on thick section S-2 glass/epoxy laminates impacted by 64 grain steel projectiles over an impact velocity range of 400 m/s to 1400 m/s. Under high velocity impact, the composite under the projectile is highly compressed and crushes into powder. A theoretical model is developed to reduce DoP data that relates the plastic/granular wave velocity, plastic/granular strain and strain rate during penetration to the strain rate dependent dynamic punch crush strength and plastic/granular erosion strain of composite for the first time in the literature. Punch crush strength is an important material property used in rate dependent progressive composite damage models. DoP experiments on thick section composites are presented to study the effects of fiber volume fraction, fabric architecture, and inelastic matrix behavior on depth of penetration and damage modes. The new data reduction methodology is used to calculate the rate dependent punch crush strength of glass/epoxy laminates.