A Study of the Damage Accumulation Process in Poly(Aryl Ether Ketone Ketone) and Its AS4 Carbon Fiber Reinforced Composites. 2. Acoustic Emission Monitoring of Damage

Poly(aryl ether ketone ketone), PEKK, is a new high performance polymeric material with numerous potential applications. In a previous paper /1/, we reported the effect of processing conditions (different crystallization temperatures and cooling rates) on the mechanical properties of carbon fiber reinforced PEKK. In this paper, the effect of processing conditions on the damage accumulation process during a quasi-static three point bend test is investigated. The points of initiation of matrix cracking, fiber fracture and interfacial failure are determined using the acoustic emission method. The acoustic data are then qualitatively correlated with load-stroke data. It is demonstrated that the damage accumulation process changes dramatically as a function of processing even though the ultimate static mechanical properties do not change substantially. This change in the damage accumulation process will affect the fatigue, impact and creep performance, even though the ultimate static mechanical properties do not change.