Characterization of failure mechanism in glass, carbon and their hybrid composite laminates in epoxy resin by acoustic emission monitoring

Fibre reinforced plastic (FRP) composites are being widely utilized in various industries because of their superior mechanical properties. Besides their advantages, failure of these composites can occur either by an individual or an associated of various failure modes which are very difficult to distinguish and discriminate the damages. This paper focuses on solving this issue, by characterizing the various failure modes in glass, carbon and their hybrid composite laminates in epoxy resin under uni-axial tensile loading with acoustic emission (AE) monitoring. AE data recorded during the testing of a pure-resin specimen and the single-layer specimen were used to identify the matrix cracking and debonding, respectively, whereas delamination was predominant in a two-layer specimen. The fibre failure was obtained from the resin impregnated single fibre strand. The parametric studies using AE amplitude, duration, AE cumulative counts, AE cumulative energy, rise angle (RA) and peak frequency were used to describe the damage mechanism of the different stacking sequence of glass fibre reinforced plastic (GFRP), carbon fibre reinforced plastic (CFRP) and their hybrid composite laminates. The mechanical parameter and AE parameter was successfully correlated for discrimination of damage mechanism. The individual failure mode of glass, carbon and their hybrid composite laminates with the most critical damage mechanisms and the time-to-failure were investigated.