CFRP laminate with autonomous sensing and enhanced impact resistance by P(VDF-TrFE) nanofibers interleaving

Structural Health Monitoring (SHM)techniques have been developed to watch over the health status of composite structures and increase their safety. However, these techniques are traditionally based on the embedding of sensors that could compromise the inherent strength of the hosting laminate. In this work, a novel approach to confer a sensing capability to Carbon Fiber Reinforced Plastic (CFRP) laminates is proposed by interleaving piezoelectric poly(vinylidene fluoride–trifluoroethylene) (P(VDF-TrFE)) nanofibers, and exploiting carbon fibers as electrodes to collect the piezoelectric signal. LVI test revealed an impact sensitivity equal to 233 mV/kN and an improved impact resistance compared to the non-sensing reference laminate, thanks to the interleaved nanofibers that hinder delamination. The impact resistance enhancement marks a paradigm shift with respect to the traditional integration of commercial sensors. Moreover, post-impact electrical measurements demonstrated the capability of detecting damage developed internally in the laminate. This innovative design introduces a new class of autonomous, self-sensing composite for aerospace applications to confer SHM capabilities without affecting or even incrementing the mechanical properties of the hosting laminate. • CFRP laminate with autonomous impact detection and improved impact resistance; • Interleaved piezoelectric P(VDF-TrFE) nanofibers; • Carbon fibers exploited as electrodes to collect the piezoelectric signal; • Interleaved nanofibers remarkably improved impact resistance by hindering delamination; • Beyond real-time sensing, the laminate features a post-event damage evaluation.