水下爆炸冲击波对圆柱形壳体结构叠加效应的数值模拟

为研究水下多点起爆冲击波的叠加效应,采用ANSYS/LS-DYNA有限元软件的流固耦合算法,首先将固支方板在水下爆炸载荷作用下的数值模拟与试验数据进行对比,将水中爆炸冲击波的超压计算值与理论值进行对比,证明了流固耦合算法的设置及相关材料参数的选取是合理的。在此基础上,针对鱼雷模拟器,进行了同一当量下单装药和四装药起爆下的系列数值运算,初步分析时差对叠加效应的影响。结果表明:当TNT当量一定时,冲击波超压值随炸距和模拟器直径的增加呈指数形式衰减; 炸距越远,模拟器直径越小,冲击波的叠加效应越强; 对于1.63 g TNT,认为多装药同时起爆的时间间隔最大不超过11 μs。给出了超压放大倍数与模拟器直径和炸距间的关系式。研究结果为大口径弹水下爆炸冲击合成毁伤鱼雷提供了理论指导。

Numerical Simulation of Superposition Effect of UnderwaterExplosion Shock Wave on Cylindrical Shell Structure

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.