Reinforced nichrome tufted CFRP laminates for self healing activation

Abstract

Carbon fibre reinforced polymers (CFRP) have been widely used in structural applications; however, in-plane damage accumulation remains a significant disadvantage. Self-healing thermoplastic matrix composites address this by melting and re-solidifying the matrix to repair damage, yet intrinsic activation without external heat sources remains a key challenge. Here, we demonstrate in-situ thermo-electrical heat generation in a glass fibre/polypropylene laminate using a through-thickness reinforced (TTR) nichrome tufted wire. The TTR serves a dual function: enhancing through-thickness mechanical integrity and acting as a resistive heating element upon electrical activation. Unlike embedded heating mats, the tufted architecture simultaneously provides structural reinforcement and localised thermal activation within a single integrated system. This heating is validated through a representative volume element thermo-electric finite element model developed in TexGen and simulated in Marc®, with temperature-dependent material properties from manufacturer datasheets validated against infrared camera measurements. The model aims to determine the optimal tuft configuration including wire spacing, current input and heating duration that minimises healing time while maximising recovery of in-plane mechanical properties. This framework directly enables industry to select tuft parameters for a given laminate without costly trial-and-error experimentation.