Non-destructive Imaging and Residual Strength of Composite Materials After Exposure to Blast Loading

Abstract

An experimental study has been conducted to evaluate the compressive residual strength of glass fiber/epoxy laminates after exposure to air blast loading. Controlled blast loading experiments were conducted using a shock tube facility which induced damage on the panels. The resulting damage in the material was quantified using non-destructive imaging technologies, specifically Terahertz (THz) and Flash Infrared Thermography (FIRT). Residual compressive strength was subsequently measured using subpanels cut from the main panel, per ASTM D7137. Furthermore, an empirical relationship has been developed to predict the residual compressive strength of the composite laminates as a function of a combined damage parameter based on individual damage mechanisms. The results show that THz and FIRT imaging can be used to quantify internal damage in a composite laminate after shock loading. Additionally, residual strength experiments show that increased shock damage causes a corresponding reduction in remaining compressive strength. The residual strength of the composite panel follows a linear trend as a function of a combined damage parameter.