Numerical Simulation of Superposition Effect of Underwater Explosion Shock Wave on Cylindrical Shell Structure

Abstract

To study the superposition effect of underwater multi-point initiation shock wave,the fluid-solid coupling algorithm of ANSYS/LS-DYNA software was used. The numerical simulation results of the rigid-supported square plate subjected to underwater explosion were compared with experimental data,and the comparison between the calculated and theoretical values of explosion shock wave was carried out. The fluid-solid coupling algorithm and related material parameters are reasonable. On this basis,a series of numerical calculations under the same equivalent single-charge and four-charge initiation were carried out for the torpedo simulator,and the influence of time difference on the superposition effect was analyzed. The results show that when the TNT equivalent is constant,the pressure value of shock wave attenuates exponentially with the increase of explosion distance and simulator diameter; the greater the explosion distance,the smaller the simulator diameter,and the stronger the shock wave superposition effect. For 1.63 g TNT,the time interval between simultaneous initiation of multiple charges is not more than 11 μs. The relationship between overpressure amplification and simulator diameter was given,as well as the relationship between overpressure amplification and explosion distance. The research results provide theoretical guidance for the underwater explosion of large-caliber projectile to synthesize damage torpedo.