Underwater structures can be seriously damaged by a metal jet associated with underwater explosion. Three main modes—Shaped Charge Jet, Jetting Projectile Charge and Explosive Formed Projectile—are included for traditional metal jets. Compared with the traditional ones, an annular jet may cause more serious damage into a target. Hence, a comparison for the entire process of annular and general jets penetration into underwater plates was analysed in this paper. Since Smoothed Particle Hydrodynamics (SPH) method has advantages of solving problems of large deformations, a modified scheme for approximating kernel gradient is used in simulation of processes of shaped charge detonation, jet formation and its penetration into underwater plates. An SPH model of an annular jet penetration into a steel target was first developed, and its numerical results were compared with experimental data. Then, models of annular and general jets associated with underwater explosion penetrating a plate were built. After that, the wave propagation in the detonation process and the formation of annular and general jets were analysed. Finally, damage characteristics of plates subjected to these two metal jets were compared.

水下爆炸可能会导致金属射流严重损坏水下结构。传统的金属射流包括三种主要模式：异形射流，射流弹丸装药和爆炸成形射弹。与传统喷嘴相比，环形喷嘴可能会对目标造成更大的损害。因此，本文分析了环形射流和普通射流穿透水下板的整个过程的比较。由于平滑粒子流体动力学（SPH）方法具有解决大变形问题的优点，因此，在模拟成形装药爆轰，射流形成及其渗透到水下板块的过程中，使用了一种近似核梯度的改进方案。首先开发了环形射流穿透到钢靶中的SPH模型，并将其数值结果与实验数据进行了比较。然后，建立了与水下爆炸穿透板块相关的环形和普通射流的模型。之后，分析了爆炸过程中的波传播以及环形和普通射流的形成。最后，比较了经受这两种金属射流的板的损伤特性。