Understanding lightning strike induced damage mechanism of carbon fiber reinforced polymer composites: An experimental study

To date, the predictive analysis of lightning-induced damage of carbon fiber reinforced polymer composites (CFRP) is challenging due to the complex multi-physical coupling effects. The current study aims to clarify the lightning-induced damage mechanism of CFRP and improve the lightning protection systems for aerospace applications. Herein, an artificial lightning strike experiment was designed to simulate the real-life conditions and investigate the influence of lightning strike on a quasi-isotropic CFRP sample. The lightning strike and corresponding degradation process were observed by using a high-speed camera and infrared thermal imaging. Moreover, lightning-induced damage was assessed by visual inspection and non-destructive testing. The damage behavior of CFRP composites was deduced by analyzing the lightning process and damage modes. The results reveal that the damage is caused by the electro-thermo-mechanical response due to lightning arc flow and Joule heating ablation due to the conductive nature of the CFRP composites. The current work provides an enhanced understanding of the failure mechanism under lightning strike and outlines instructional suggestions to refine the numerical model of lightning-induced damage of CFRP for further study.