Mechanical behaviour and damage evaluation by acoustic emission of composite materials

The aim of the present study is to investigate the mechanical behaviour of cross‐ply laminates under static tensile and buckling loading. Different cross‐ply laminates constituting of carbon fibers (CFRP), hybrid fibers (HFRP) and glass fibers (GFRP) in an epoxy matrix were considered. This work is also interested in identifying and characterizing the local damage in the composites with the use of acoustic emission method (AE).

The cross‐ply laminates are differentiated by the stacking sequences, thickness of 90° oriented layers and reinforcement. They are subjected to the static tensile and buckling load. The damage investigation is reached by the analysis of acoustic emission signals collected from static buckling tests.

The results show the effects of reinforcement type, stacking sequences and thicknesses ratio of 90° and 0° layers on the stiffness, failure load and displacement. A cluster analysis of acoustic emission data is achieved and the results are correlated to the damage mechanism of specimens under buckling tests.

The analysis of acoustic emission signals collected from static buckling tests under loading levels of 40, 60 and 100 per cent of the static failure load allows the damage investigation in cross‐ply laminates.