Effect of patch hybridization reinforcements and environmental conditions on residual strength and damage modes of repaired composite laminates

Abstract

The main objective of this work is to improve the residual strength and structural integrity of damaged glass epoxy composite laminates using adhesively bonded external patch repairs In this thesis a novel adhesively bonded external patch repair configuration has been introduced mainly to improve the residual strength and structural integrity of damaged glass epoxy composite laminates under transverse loads and environmental service conditions i e hydrothermal ageing Furthermore the effect of various newlinedesign parameters and processing conditions in the patch repair has also been newlineinvestigated under in plane loads i e compression and tensile loads as the newlinelargest number of events in real life condition may be applied out of plane newline transverse as well as in plane to the structure Due to ease of real time newlinemonitoring of dynamic changes within an anisotropic composite the Acoustic newlineEmission AE monitoring and Digital Image Correlation DIC has been used to investigate the damage mechanisms and localize damage in the repaired newlinespecimens newlineThe mechanical properties retention process includes three main newlinesteps Initially the individual and associated effects of post cure temperature newlineand reinforcement phases on the repair performance of adhesive reinforced newlinerepairs in damaged glass epoxy composite laminates were investigated newline newline