Investigation on Shock Response of Multi-Link Underwater Vehicles Subjected to Mid-to-Far Field Underwater Explosions

To investigate the structural shock response and load transfer characteristics of different missile canister configurations with varying internal connection vibration isolation stiffness under multi-directional mid-to-far field underwater explosion loads, an integrated parametric dynamic model of the missile-canister-vehicle system was established in Abaqus via Python, and acoustic-structure coupling simulation was performed. The improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) method was applied to process time-domain responses of key positions for comparative time-frequency analysis. Results show that the most severe load condition occurs with underwater explosion directly below the structure, yielding the highest average response at dangerous points; the mildest condition occurs with explosion directly above, with the lowest corresponding response. A single-canister structure with rigid bottom missile connection exhibits the worst vibration isolation performance, while a double-canister structure with low-stiffness bottom isolation achieves the optimal performance. The effects of explosion attack angle and canister configuration on structural shock response are significantly greater than that of bottom isolation stiffness. Strong high-central-frequency shock responses occur at the top and bottom joints between the canister and vehicle hull, requiring targeted anti-shock and vibration protection. The results provide a reference for safety protection and anti-shock research of underwater vehicles under mid-to-far field underwater explosion impacts.