Dynamic response and damage behavior of composite unmanned aerial vehicle subjected to blast of charge with spherical fragments

Abstract This study investigates the damage mechanisms and characteristics of carbon fiber/polymethacrylimide (PMI) foam sandwich unmanned aerial vehicle (UAV) structures subjected to combined actions of shock wave and fragment impact loading through integrated theoretical analysis, experimental testing, and numerical simulations. A theoretical approach was utilized to approximate the sequence of interactions between fragments and shock waves. The findings reveal that, in far‐field tests, the UAV primarily suffers damage from fragments, with failure modes resulting from the impact load of these fragments including perforation, fiber breakage, matrix cracking, delamination, and PMI core crushing. Conversely, in near‐field tests, the UAV experiences significant damage from the combined actions of shock waves and fragments, leading to observable bending, deformation, and fracturing of the wing. The structured arbitrary Lagrangian–Euler (S‐ALE) and CONWEP algorithm in LS‐DYNA are employed to clarify the interaction mechanisms between fragments and shock waves. These methods simulate the damage process of the UAV structure under the combined actions of shock waves and fragments while examining the influence of various factors on the energy absorption characteristics of the structure. This research provides valuable insights into the damage sustained by carbon fiber/PMI foam sandwich UAVs under the combined action of shock waves and fragments. Highlights Analyzed dynamic response and damage of composite UAV under blast‐fragment loading. Shock wave–fragment interaction mechanisms and action sequences were analyzed. A numerical model based on the S‐ALE and CONWEP algorithms was constructed. Discussed the impacts of blast distance, charge mass, and fragment parameters on damage. Analyzed energy absorption in diverse structures under extended test conditions.