The 7th International Conference on Material Strength and Applied Mechanics
(MSAM 2024)

Abstract: Carbon fiber reinforced composites (CFRCs) have been increasingly utilized in aircraft to replace metal alloys due to their low density and excellent specific strength and stiffness. However, the use of semi-conductive CFRC structure in an aircraft presents a threat to flight safety from lightning strikes. Compared to metallic counterparts, CFRCs exhibit much lower electrical conductivity, which may not readily conduct away a high lightning current. As a result, the injection of lightning current causes intense resistive heating in the CFRCs, leading to severe thermal ablation and delamination. This study developed a coupled electrical-thermal-mechanical finite element (FE) model to accurately predict the thermal and mechanical damage to CFRCs during a lightning strike event. The dynamic response and damage evolution in CFRCs were predicted by the FE model and compared with experimental results from simulated lightning strike tests. It was found that the FE-predicted results regarding lightning strike damage/depth and dynamic responses were consistent with existing experimental data, demonstrating the effectiveness of the proposed FE model. Subsequently, a multi-objective optimization method was established to optimize the geometric and electrical parameters of a dual-layer lightning strike protection system for both high protection effectiveness and lightweight. Finally, two lightweight protective strategies were proposed for excellent lightning strike protection as well as electromagnetic interference shielding.

Keywords: Carbon fiber reinforced composite, lightning strike, damage, protection.

Acknowledgements: The authors acknowledge financial support from the National Natural Science Foundation of China (Grant number: 12172257).

Biography: Prof. Kunkun Fu is currently working as a Deputy Dean of the School of Aerospace Engineering and Applied Mechanics at Tongji University, P.R. China. He was awarded a national early-career scientist fellowship in 2018 after he worked as a Postdoctoral Research Fellow at the University of Sydney and the University of New South Wales Canberra. Prof. Fu’s major research interests include the failure mechanics of composite structures and additive manufacturing of fiber reinforced composites. He has strong expertise in numerical modelling of composite structures in various engineering areas in particularly under extreme conditions such as lightning strike and impact. So far, he has published over 100 peer-reviewed journal publications and served as the journal editorial member of Coatings and Chinese Quarterly of Mechanics, the standing committee member of Shanghai Society of Theoretical and Applied Mechanics, and the committee member of Shanghai Society of Composite Materials.