舰艇抗冲瓦水下爆炸流固耦合冲击动力学模型

 为更好的反映水下爆炸作用下舰艇抗冲瓦芯层复杂结构动力学特性,基于多自由度动力学、Taylor平板理论一阶DAA法,提出了舰艇抗冲瓦在水下爆炸冲击波载荷作用下的流固耦合与冲击动力学模型。抗冲瓦冲击响应分为3个阶段,I阶段是在冲击载荷作用下的一维流固耦合开始阶段,水中气穴开始产生;II阶段芯层开始被压溃,但此时抗冲瓦表层速度开始降低,水质点的附加冲量起到重要作用;III阶段是从减速到回弹阶段,抗冲瓦在弹性恢复力和流体阻尼共同作用下产生减速和反弹。3个阶段的理论模型揭示了水下爆炸作用下抗冲瓦的冲击响应过程。通过理论模型和算例研究发现,所提出的模型能很好的反映具有复杂芯层结构的抗冲瓦在水下爆炸冲击波作用下的缓冲与耗能机理,抗冲瓦芯层密度对其缓冲效果影响显著。这些性能特点可以用于在给定质量情况下对抗冲瓦进行几何优化设计。

A Fluid-structure Coupling and Dynamic Model of Ship Anti-shock Layer for Underwater Explosion Wave Isolation

A fluid-structure coupling and dynamic model of ship anti-shock layer for underwater explosion wave isolation is developed to describe the complex structural dynamics and hydrodynamics characteristics of the anti-shock layer due to underwater explosion based on the multi-DOF dynamic theory, Taylor's flat plate model and DAA1 methods. The anti-shock layer shock response is split into three sequential steps: stage I is the one-dimensional fluid-structure interaction problem during the blast loading event, and results in a accelerated motion of the outer face sheet, and the cavitation occur in the water; during stage II the core crushes while the velocity of the outer face sheet bring down, additional impulse due to the water particles play an important role; stage III is the retardation phase over which the anti-shock layer is brought to rest by elastic restoring force and fluid pressure. The third-stage analytical procedure is used to obtain the dynamic response of the anti-shock layer to an underwater explosion. The analytical procedure and case study indicate the proposed model can deal with the ship anti-shock layer with complex core structures and the core density have a significant impact on the cushion effects of the ship anti-shock layer. The influence of the core density to the cushion performances is analyzed. These performances can be used to determine the optimal geometry to maximize shock resistance for a given mass of the anti-shock layer.