A Finite Element Framework to Implement Lightning Induced Load
摘要
Carbon Fiber Reinforced Polymer (CFRP) composites are increasingly used in modern aircraft due to their high strength-to-weight ratio, directional stiffness, and improved payload capacity. However, their low electrical and thermal conductivity makes them highly vulnerable to damage from lightning strikes. This study presents an advanced finite element framework for simulating lightning strike effects on CFRP, to predict the thermal and mechanical responses. The material failure model is based on Hashin/Puck criteria, accounting for damage initiation and evolution under high heating and strain rates. Temperature-dependent material properties are defined for a range of 25 °C to 3316 °C, considering heating rates up to 20,000 °C/min and strain rates between 0.1 s⁻1 and 3.5 × 105 s⁻1. The model includes a bivariate Gaussian representation of the arc root interaction with CFRP, where the arc root radius initiates at 2 mm and expands to 12 mm. A two-stage simulation is performed: a coupled thermal-electric analysis followed by a mechanical analysis to capture thermal-induced stresses. The proposed approach improves the accuracy of lightning damage prediction, with results showing that incorporating a spatially varying load distribution reduces error in damage extent estimation to within 10%. This model offers a more realistic and predictive tool for assessing lightning strike effects on CFRP components.