The Analysis of the Impact Factors on the Interaction Mechanism between Lightning Arc and CFRP Structure with Fastener Under Lightning Strike Conditions

There is a complex dynamic coupling process between lightning arc and carbon fiber reinforced polymer (CFRP) structure with the fastener during lightning attachment. Based on Magneto Hydro Dynamics (MHD) theory, this paper conducts an in-depth analysis of the time-accurate response of attached arc under the influence of lightning current, exploring the factors affecting the nonlinear interaction mechanism between CFRP structure with the fastener and electrical arc. The research focuses on the presence of fasteners, the size of the discharge gap, and the effects of different discharge current waveforms on the interaction mechanism between the arc and the CFRP structure. By establishing physical models of discharge under various conditions, this paper simulates the evolution of the electrical arc during current injection. It comprehensively analyzes how changes in the structure’s current conduction path, surface temperature distribution, and the arc plasma’s spatiotemporal thermal conduction characteristics affect the interaction between the lightning channel and the composite material. Additionally, the state variable setting method is applied to track the expansion behavior of high-temperature region on the surface of CFRP structure and evaluate the dynamic evolution of the interaction between the arc and the structure. The results showed that the fastener play a crucial role in the process of current conduction, where the differences in material properties between the fasteners and CFRP result in a preferential path for current conduction along the depth of the fastener assembly which significantly affects the coupling between the lightning channel and the CFRP structure. Variation in the discharge gap length results in a hysteresis phenomenon in arc attachment behavior. The interaction relationship between changes in the surface state of CFRP and arc evolution is particularly evident. This work presents a method for studying coupled behavior between lightning arc and CFRP structure with fastener under various discharge conditions.