Control of Compressive Fatigue Delamination Propagation of Impact Damaged Composites Using Discrete Thermoplastic Interleaves

A delamination damage control and management concept is demonstrated showing how, through selective placement of discrete thermoplastic film interleaves, it is possible to manipulate the formation of impact damage and control its subsequent propagation during compressive fatigue cyclic loading. Under cyclic loading the gradual growth of impact damaged delamination was shown to be arrested by the discretely embedded interleaved strips. This technique then resulted in the growth of delamination away from the arrested sites effectively moving the damage zones and thus confirming the concept of delamination damage control. By managing the propagation of delamination, significant improvements to the compression after impact fatigue life of the composite were achieved. The proposed method is cost-effective and can be implemented with minimal disturbance to the global laminated composite properties. With an optimised design approach to managing delamination damage, safe ‘damage tolerant’ composite structures can be realised with significant weight saving benefits.