Experimental study of impulse-current-induced electrical, arc, thermal, and mechanical multiphysics coupling on carbon fiber-reinforced polymer composites

A detailed understanding of the multi-physical coupling effects in carbon fiber-reinforced polymer (CFRP) composites subjected to lightning strikes remains limited. This study proposes a set of systematic experimental methods and techniques integrating electrical, arc, thermal, and mechanical measurements. Using these methods, the complex behaviors induced in unidirectional CFRP composites under 8/20 μs impulse current injection were experimentally investigated, revealing the interrelationships and temporal sequences among the various multiphysical phenomena. Results indicate that both the lightning current injection and arc attachment zones exhibit elliptically distributed with different orientations. At the lightning attachment center, superimposed lightning thermal effects cause severe resin pyrolysis, with arc heating playing the dominant role. The associated heat accumulation leads to a delayed occurrence of surface material explosion shockwaves, with the lightning impact pressure peaking approximately 40 μs after the lightning strike. The impulse of lightning impact loads at the lightning attachment point at 12 kA is approximately 635.5 N·μs. At 15 mm outward, the arrival of arc-expansion shockwaves is further delayed, with the impact strength and impulse magnitude reduced by approximately 34.5 % and 50 %, respectively. This paper provides valuable experimental data for the development of an electro-thermal-impact synergistic damage model for CFRP composites.