Numerical Simulation of Damage Behavior in Graphene-Reinforced Aluminum Matrix Composite Armatures under Multi-Physical Field Coupling

With the rapid advancement of electromagnetic launch technology, enhancing the structural stability and thermal resistance of armatures has become essential for improving the overall efficiency and reliability of railgun systems. Traditional aluminum alloy armatures often suffer from severe ablation, deformation, and uneven current distribution under high pulsed currents, which limit their performance and service life. To address these challenges, this study employs the Johnson–Cook constitutive model and the finite element method to develop armature models of aluminum matrix composites with varying heterogeneous graphene volume fractions. The temperature, stress, and strain of the armatures during operation were analyzed to investigate the effects of different graphene volume fractions on the deformation and damage behavior of aluminum matrix composite armatures under the multi-field coupling of electromagnetic, thermal, and structural interactions. The results indicate that, compared to the 6061 aluminum alloy matrix, the graphene-reinforced aluminum matrix composite armature significantly suppresses ablation damage at the tail and throat edges. The incorporation of graphene notably reduces the temperature rise during the armature emission process, increases the muzzle velocity under identical current excitation, and mitigates directional deformation of the armature. The 1 wt.% graphene-reinforced aluminum matrix composite armature demonstrates better agreement with experimental results at a strain rate of 2000 s−1, while simultaneously improving stress-strain response, reducing temperature rise, and improving velocity performance.