中文摘要：

该文以轻质金字塔点阵夹层平板结构为对象，对其在不同撞水速度下（1ms～6m／s）的流．固耦合动力学行为进行数值和理论计算分析。首先建立了气．液．固三相数值模型，通过详细计算获得了砰击压力的分布特征与结构砰击变形特征，分析表明当砰击压力脉宽和结构自振周期（湿模态）之比大于4时流．固耦合效应不显著。与同等质量实体板相比，轻质金字塔点阵夹层平板平均流一固砰击压力与结构最大变形均显著降低，而且存在“局部气垫”现象（在实体平板撞水的过程中未发现该效应）。提出一种将砰击变形位移场分解为总体变形和局部变形，然后进行叠加的计算模型，该种工程近似计算方法获得的变形估算值与数值计算结果吻合较好。

英文摘要：

The fluid-solid interaction （FSI） dynamic responses for a Light Weight Pyramidal Sandwich Plate Structure （LWPSPS） under different water-impact velocities （lrn/s-6rn/s） are investigated numerically and theoretically. The finite element method （FEM） computational model of multi-physics （air-water-solid） is built and the characteristics of slamming pressure and structure deformation are obtained based on the proposed 3D multi-physics FEM model. Hydroelastic analysis demonstrates that the FSI effect is weak when the ratio of time of water impact duration to the wet natural period of a LWPSPS is higher than 4. Numerical results show that both the average slamming pressure and the maximum deformation of LWPSPS are much lower than those of monolithic plate with same mass. Furthermore, a phenomenon called ＂local air cushion＂ is observed for LWPSPS which is not existed for a monolithic plate. In the study, an engineering estimation method to predict the maximum deformation of the LWPSPS is proposed, in which the total deformation is divided into two parts, i.e. the local field deformation and the global field deformation. Good agreement between the FEM numerical results and those obtained from the proposed engineering estimation method is achieved.