Study on damage criterion of the typical barrel subjected to tungsten fragment impact considering artillery firing loads and multi-factor effects

The gun barrel is the critical component of artillery weapons exposed outside the armor and plays a key role in projectile launching. At present, studies on the vulnerability of gun barrels subjected to fragment impact remain limited. In this study, a vulnerability assessment framework for the gun barrel under fragment impact was established, consisting of four sequential stages: experimental testing, finite element (FE) simulation, functional damage assessment, and prediction of damage probability. In the experimental testing stage, the failure modes of the barrel induced by fragment penetration were identified based on the damage characteristics after impact, and the FE simulation methodology was validated. In the FE simulation stage, by controlling variables, the effects of fragment mass, impact velocity, incident angle, and barrel wall thickness on penetration outcomes were obtained, and a theoretical model for predicting barrel damage after fragment penetration was established. The model predicts key damage parameters and critical thresholds for different fragments, with predictions showing great agreement with experimental data. Based on the damaged barrel, verification models for structural strength and firing performance considering artillery firing loads were developed. The critical allowable crater depth and bulge height thresholds at different barrel locations were determined. Finally, considering the randomness of impact direction and location, a damage criterion calculation model was established, which can effectively predict the damage probability of the barrel under fragment impact. The calculation shows that the minimum fragment kinetic energy triggering the onset of barrel failure is 2205 J. When the fragment kinetic energy ranges from 2205 J to 32500 J, the damage probability increases from 0 to 0.235. The criterion model accounts for comprehensive influencing factors, and the establishment method is broadly applicable, providing a reference for developing damage criteria for other gun barrels.