Experiment research on damage effect of underwater multipoint synchronous explosion on semi-cylindrical shell

This study uses experimental methods to investigate the damage characteristics of typical underwater structures under synchronous array charge underwater explosions. Small-scale underwater explosion tests are conducted in a water tank to study the damage characteristics of reinforced annular cylindrical shells under the detonation of a three-charge array and an equivalent single charge. A comparative analysis is conducted to explore the effect of fixed spacing triangular and linear charge arrangements on the structural damage characteristics. The results show that shell collapse is observed under array charge conditions, with the deformation range increasing by 39 % compared to the single charge condition. In terms of backplate damage, the impact of array charges is more significant, and severe secondary damage is observed. The ALE method is further employed to establish a numerical model of underwater array explosion damage for a semi-cylindrical shell. The impact of different spacings for two arrangement configurations is then analyzed. In the triangular arr angement, when the spacing-to-radius ratio exceeds 6, the damage effect starts to rapidly decrease. In the linear arrangement, the rupture size is inversely proportional to the spacing ratio, while the plastic deformation area is directly proportional to the spacing ratio.