火炮发射与控制学报

电枢-轨道接触界面的电流密度与接触压力动态分布，是诱发电磁发射过程中熔化、磨损等物理现象的核心因素。现有解耦或单向耦合模型难以揭示多物理场耦合下界面的动态接触特性，导致仿真结果与实验观测存在偏差。为此，建立了电磁-结构双向耦合有限元模型，对电枢装填-发射全过程开展数值模拟，探究接触界面电流密度与接触压力的时空演化规律。结果表明：电流上升阶段，机械预紧力主导的接触压力分布会重构电枢内的电流传导路径，使电枢电磁压力较理想接触条件显著降低；电磁压力占据主导后枢轨形成全接触状态，电流密度分布趋近理想接触特征。基于双向耦合模型得到的接触面温度场时空分布规律，与实验回收电枢烧蚀形貌高度吻合。研究结果可为电枢表面烧蚀研究和过盈配合优化设计提供参考依据。

The dynamic distribution of current density and contact pressure at the armature-rail interface is a primary factor inducing physical phenomena such as melting and wear during electromagnetic launch. Existing decoupled or one-way coupled models cannot accurately reveal the dynamic contact characteristics of the interface under multi-physics coupling conditions,leading to deviations between simulation results and experimental observations. To address this issue, a two-way electromagnetic-mechanical coupled finite element model was established to simulate the armature loading and launch process, thereby investigating the spatiotemporal evolution of current density and contact pressure at the contact interface. The results indicate that during the current rising stage, the contact pressure distribution dominated by the mechanical preload reconstructs the current conduction paths within the armature, causing the electromagnetic pressure on the armature to be significantly lower than that under ideal contact conditions. After the electromagnetic pressure becomes dominant, the armature-rail interface transitions to a full-contact state, and the current density distribution approaches the ideal contact characteristics. Furthermore, the spatiotemporal distribution of temperature field at the contact interface based on the two-way coupled model exhibits an excellent agreement with the ablation morphology of recovered armatures in experiments. The findings provide a reference for the study of armature surface ablation and the optimization design of interference fit.