超聚能装药近场水下爆炸对舷侧防护结构的毁伤机理研究

The process of naval structures subjected to hypercumulation associated with near-field underwater explosion is strongly nonlinear, with problems of high-speed jet impact, strong discontinuities and damage of structures, etc. Structures can be severely damaged by a strong discontinuous shock wave, a high-speed metal jet and a non-spherical bubble pulsation. Hence, a hybrid algorithm fully utilizing advantages of both Smooth Particle Hydrodynamic (SPH) method and Finite Element Method (FEM) is proposed and a SPH-FEM model of structures subjected to the hypercumulation associated with near-field underwater explosion is established. Based on above, the discontinuous caused by shock wave, the plastic flow of the metal jet, the non-spherical pulsation of the bubble as well as the cavitation characteristic of the fluid are catched with high resolution. The three-phase coupling system for gas-liquid-solid formed by the metal jet, the shock wave, the bubble as well as the cavitation is investigated. Finally, the combined damage variable is introduced to study the damage mechanism of broadside defensive structures subjected to the coupling loads of the metal jet, the shock wave as well as the bubble. This research will provide theoretical and technical support for the shock resistance of warships and the development of weapons and ammunition.

超聚能装药近场水下爆炸涉及高速射流冲击、多相强间断、结构撕裂等强非线性问题，产生的强间断冲击波、高速金属射流以及非球状气泡脉动等毁伤元素可对舰船结构造成毁灭性打击。本研究以此为背景，采用超聚能装药结构提高金属射流的侵彻能力，综合利用无网格光滑粒子流体动力学SPH方法和有限元FEM方法各自的优势，建立三维超聚能装药近场水下爆炸SPH-FEM瞬态冲击流固耦合模型与计算方法；在此基础上，考虑流场的空化效应，高分辨率捕捉冲击波的强间断、金属射流的塑性流动、气泡的非球状特性以及流场的空化特性，探究空化与冲击波、金属射流以及气泡形成的气-液-固三相耦合系统，得到冲击载荷的形成机理；最后，引入复合损伤因子，结合实验研究冲击波-金属射流-气泡冲击载荷联合作用下舷侧防护结构的破坏机理。研究成果可为武器弹药研制与舰船抗冲击研究提供理论和技术支撑。

本研究综合利用无网格光滑粒子流体动力学SPH方法和有限元FEM方法各自的优势，建立了三维超聚能装药近场水下爆炸SPHFEM瞬态冲击流固耦合模型与计算方法；在此基础上，考虑流场的空化效应，高分辨率捕捉冲击波的强间断、金属射流的塑性流动、气泡的非球状特性以及流场的空化特性，探究空化与冲击波、金属射流以及气泡形成的气-液-固三相耦合系统，得到冲击载荷的形成机理；最后，引入复合损伤因子，结合实验研究了冲击波-金属射流-气泡冲击载荷联合作用下结构的破坏机理，研究成果可为武器弹药研制与舰船抗冲击研究提供理论和技术支撑。