Delamination characteristics and relationships of CFRP laminates under laser-induced shockwaves with different laser parameters

Abstract

Moving beyond conventional reliance on laser power density for damage assessment, this work directly links three key laser parameters—energy, spot diameter, and pulse width—to damage outcomes. Constructed physical response model integrated with Photonic Doppler Velocimetry (PDV) signals introduces a novel parameter, R, to quantify the laminate’s residual vibrational energy and damage state. Results show R’s clear advantage: it effectively characterizes damage directly from the shock response. The R-energy curve reveals three distinct damage progression stages—linear accumulation, energy absorption saturation, and stable propagation—which are difficult to differentiate and quantify using power density or ultrasonic imaging alone. By establishing the functional relationship F(x, y, z) = R, this study enables damage state prediction for specific laser parameters, validated by ultrasonic B-scanning in T300/AK8210 resin-based carbon fiber reinforcement. This approach facilitates efficient, direct assessment of internal damage in real time, minimizing reliance on post-hoc non-destructive testing. It holds significant potential for optimizing laser shock processes and advancing structural health monitoring of composites.