Acoustic emission detection of damage induced by simulated environmental conditioning in carbon fiber reinforced composites

High performance composites for structural applications in aviation are sensitive to aging from altering environmental conditions. For instance, the stiffening behavior of glass fiber/polyester composites used by the wind turbine industry has already been demonstrated in previous work of the authors. Now, passenger aircrafts from such composites are increasingly entering into service. It is crucial, thus, to study the exposure of high performance materials to aging-inducing environmental conditions such as varying temperature, humidity, ultraviolet radiation, and assess their impact on mechanical response of such composites. In this work we have applied acoustic emission analysis to study the effects of simulated environmental aging on carbon fiber reinforced composites. Signals collected from three point bending testing of pristine specimens as well from thermally shocked and environmentally aged ones. Signal parameters were afterwards plotted and studied in correlation with the specimens' mechanical response.