A developed energy-dependent model for studying thermal shock damage and phase transition of composite reinforced panel subjected to lightning strike

Lightning strikes generate large amounts of energy. Thus, composite structures subjected to lightning strikes undergo significant physicochemical changes. In this study, the thermal shock damage and three-phase transition of a composite reinforced panel were investigated through a numerical simulation, an experiment, and ultrasonic C-scanning. An anisotropic constitutive model and PUFF equation of state (EOS) were proposed to study the damage behaviors of composite materials. The dynamical damage behaviors and three-phase transition of the composite reinforced panel were simulated using the proposed constitutive model and PUFF EOS. Finally, a lightning experiment and ultrasonic C-scanning were conducted to validate the numerical results. Obvious fiber upwarping and swelling were observed in the numerical simulation. The melted and vaporized materials caused a reverse thermal shock effect, which led to concave pits, buckling and internal damages in the composite reinforced panel. The numerical results were compared with experimental results and scanning results to validate that the proposed constitutive model and modified PUFF EOS can be well used to simulate the dynamical damage behaviors of composite materials. The simulated damage behaviors of the composite reinforced panel agreed well with the behaviors observed in the experiment.