Damage characteristics and parameter influence laws of laser-shocked delamination of CFRP laminates

Abstract

Laser Bond Inspection (LBI) is an emerging technology that employs the mechanical effect of laser-induced shock wave to quantitatively evaluate the interfacial strength of composite materials, particularly for Carbon Fiber Reinforced Polymer (CFRP) laminates. This process requires an in-depth understanding of the damage characteristics of laser-induced delamination and the influence of laser parameters on the coupling behavior of laser-induced shock wave propagation. This work develops a new three-dimensional constitutive model specifically designed for CFRP laminates subjected to laser shock. Combining empirical testing with numerical simulation results, it reveals the different damage characteristics and mechanisms of laser-induced delamination, with a particular focus on elucidating the damage mechanisms and sequence of multi-layer delamination occurrence. Meanwhile, the threshold for single-layer delamination and the transition threshold to multi-layer delamination are provided, offering a reference range of power density for conducting LBI testing. Furthermore, the effects of different laser parameters on delamination characteristics and shock wave propagation patterns are revealed, providing guidance for laser parameter design to regulate the internal stress distribution within laminates.