Abstract
The damage evolution of armature-rail contact surfaces in electromagnetic railguns under high-speed sliding directly determines the launching accuracy and service life of weapon systems. However, the invisibility of the launching process brings inherent limitations to related research. Traditional multiphysics simulations ignore the real-time feedback of wear on interface geometry and mechanical states, which causes divergence and distortion of positive feedback in the late stage of calculation.To address this theoretical bottleneck, this study develops an electromagnetic-thermal-mechanical staggered bidirectional sequential coupling model with real-time wear correction. On the basis of this model, the evolution features and patterns of multiphysics parameters under real launching conditions are systematically revealed.The work quantitatively decouples the individual contributions and dominance shift of preload, electromagnetic force and thermal expansion force on the contact interface across the full launch cycle. It also clarifies the stress attenuation triggered by material loss due to wear. Cross-validation of different parameters shows that the degradation of local contact impedance caused by skin effect and wear drives the spatial reconstruction of current paths. The spatiotemporal distribution of electro-thermal coupling under wear shapes the fluctuation of interface contact resistance, and gives a self-consistent explanation for the nonlinear evolution of armature dynamics.The 3D wear morphology reconstructed by simulation matches well with the microscopic scanning results of armatures collected after real launching tests. The consistency verifies the reliability of the proposed model and the revealed patterns. This study breaks the limitations of traditional one-way coupling simulations, and offers a new theoretical tool for investigating the evolution mechanism of high-current sliding contacts under extreme working conditions.