摘 要

船舶在海上航行与作业过程中，将不可避免地与波浪发生相对冲击，产生砰击现象。砰击载荷会使船体局部结构发生破坏，严重时甚至会造成海难事故。而轻质金属夹层板在砰击载荷作用下，其芯层会产生较大的塑性变形，可以较好地吸收外部砰击能量，因此其具有较好的能量吸收特性。因此，轻质金属夹层板在船舶结构安全与冲击防护方面具有巨大的应用前景。

本文将利用有限元软件ABAQUS，研究船用夹层板在砰击载荷下的动态响应和能量吸收特性。首先，根据参考文献中的相关参数，开展加筋板在砰击载荷作用下的动态响应数值仿真研究，获取加筋板中心点的变形时间历程曲线，然后将所得结果与参考文献中的结果进行对比，验证了本文所用仿真方法的可靠性。然后，利用上述数值仿真方法，进行了泡沫铝夹层板与蜂窝铝夹层板在砰击载荷下的动态响应和能量吸收特性研究。结果表明，蜂窝铝夹层板的抗变形能力强于泡沫铝夹层板。且还发现，不同结构形式，同一脉冲载荷输出的能量不同。在此基础之上，对蜂窝铝夹层板的砰击动态响应开展了参数影响研究，分析了上下面板厚度以及面板厚度分配比、蜂窝芯层厚度、脉冲载荷幅值及长度和蜂窝胞元边长及胞元壁厚对蜂窝铝夹层板动态响应与能量吸收的影响规律。结果表明：增加上下面板厚度以及蜂窝胞元壁厚，夹层板抵抗砰击变形的能力增强；增大上下面板厚度比以及芯层厚度，夹层板抵抗砰击变形的能力基本不变，但可减小上面板与芯层在砰击载荷下的变形损伤；夹层板下面板变形与脉冲载荷幅值呈近似线性变化关系；而增加脉冲载荷长度，夹层板下面板变形减小；在一定范围内增大蜂窝胞元边长，可减小夹层板下面板在砰击载荷下的变形。

本文的研究结果可以为船舶结构抗砰击设计提供一定的参考依据，具有一定的理论意义和工程应用价值。

关键词：船用夹层板；数值仿真；砰击载荷；动态响应；能量吸收

Abstract

In the process of ship sailing on the sea, the ship will inevitably experience relative impact with the water, resulting in the phenomenon of slamming. The slamming loads may lead to damages on the local structure of the ship, and even cause the marine accident. Under slamming load, the core of the light metal sandwich plate will produce large plastic deformation, indicating the sandwich plate has excellent performance of energy absorption. Therefore, the light metal sandwich plate has a great application prospect in the safety and impact protection of ship structure, which can avoid the damages and failure of ship structure when it is subjected to slamming.

In this paper, the dynamic responses and energy absorption characteristics of sandwich plate under slamming load were studied by using finite element software ABAQUS. Firstly, the dynamic responses of stiffened plate under slamming load was studied by numerical simulation, and the time history curve of center point deflection of stiffened plate was obtained. Then the simulation results were compared with those of the references to verify the reliability of the simulation method applied in this paper. Besides, the dynamic response and energy absorption characteristics of aluminum foam sandwich plate and honeycomb sandwich plate under slamming load were studied by using the numerical simulation method. The results showed that, the honeycomb aluminum sandwich plate had better anti-slamming performance. On this basis, the influence of parameters on the dynamic response of honeycomb aluminum sandwich plates suffering from slamming loads was studied, the influences of the thickness of the top and bottom face sheets and the ratio of thickness distribution of the panels, the thickness of the honeycomb core, the amplitude and length of the pulse load, the size of the honeycomb cell and the thickness of the cell wall on the dynamic response and energy absorption of the honeycomb aluminum sandwich plates were analyzed. The results showed that, the ability of resisting slamming deformation of sandwich plates was enhanced by increasing the thickness of top and bottom panels and the cell wall thickness of honeycomb. While, the ability of resisting slamming deformation of sandwich plates was basically unchanged when increasing the thickness ratio of top and bottom face sheets as well as the thickness of the core, however, the deformation damage of the top face sheet and the core will decline under the slamming load. Meanwhile, the deformation of the bottom face sheet approximately increased in form of linear with the amplitude of the impulse. When the duration of the impulse increased, the deformation of the bottom face sheet decreased. The deformation of the bottom face sheet under slamming load will decrease when increasing the cell length of the honeycomb core in a certain range.

The results of this paper can provide some reference for the design of the ship structure considering the slamming loads, and have some values on the theoretical studies and the engineering application.