航行体梯度密度式头帽结构设计及降载性能分析  

STRUCTURAL DESIGN AND LOAD REDUCTION PERFORMANCE ANALYSIS OF GRADIENT DENSITY HEAD CAP OF VEHICLE

作　　者：施瑶[1,2] 刘振鹏 潘光 高兴甫[1,2] Shi Yao;Liu Zhenpeng;Pan Guang;Gao Xingfu(School of Marine Science and Technology,Northwestern Polytechnical University,Xi’an 710072,China;Key Laboratory of Unmanned Underwater Vehicle Technology,Ministry of Industry and Information Technology,Xi’an 710072,China)

机构地区：[1]西北工业大学航海学院,西安710072 [2]无人水下运载技术工业和信息化部重点实验室,西安710072

出　　处：《力学学报》2022年第4期939-953,I0003,共16页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(U21B2055,52171324);中央高校基本业务费(3102019JC006)资助项目。

摘　　要：针对航行体在以大于100 m/s的速度高速入水过程中承受巨大的冲击载荷可能导致的结构损坏、弹道失控等现象,而现有的缓冲措施降载能力有限的难题,本文设计了一种航行体高速入水梯度密度式缓冲头帽,确保航行体能够高速安全入水,并给出了详细的设计过程.同时基于ALE(arbitrary Lagrangian-Eulerian)算法建立了航行体带缓冲头帽高速入水数值计算模型,且数值计算的结果与试验测试数据具有较好的一致性.然后在此基础上,开展了航行体带梯度密度式缓冲头帽高速入水降载特性的数值研究,探究了双层缓冲件不同分层厚度、正负密度梯度排列以及层间密度差等重要参数对缓冲头帽能量吸收以及缓冲降载效果的影响规律,并进行了大尺度模型高速入水冲击测试试验,根据航行体模型干模态分析时的二阶弯曲模态固有频率对试验数据进行滤波处理.研究结果表明,在本文所研究的范围内,分层的缓冲件相比较于不分层的缓冲件表现出更强的冲击能量吸收效果,且缓冲件吸收的冲击能量随着分层数的增加而增加;负密度梯度排列的缓冲件其缓冲能力强于正密度梯度的缓冲件;当层间密度差越大时,冲击能量的损耗也将越大,缓冲头帽的降载效果越好.Aiming at the problem that the structure damage and trajectory out of control may be caused by the huge impact load when the vehicle enters the water at a high speed of more than 100 m/s,and the load reduction capacity of the existing buffer measures is limited,a gradient density buffer head cap for the vehicle entering the water at a high speed is designed in this paper to ensure that the vehicle can enter the water safely at a high speed,and the detailed design process is given.At the same time,based on the ALE(arbitrary Lagrangian-Eulerian)algorithm,a numerical calculation model of high-speed water entry of the vehicle with a buffer head cap is established,and the results of numerical calculation are in good agreement with the experimental data.Then,on this basis,the numerical research on the characteristics of high-speed water entry and load reduction of the vehicle with gradient density buffer head cap is carried out,and the influence laws of important parameters such as different layer thickness,positive and negative density gradient arrangement and interlayer density difference of the double-layer buffer on the energy absorption and load reduction effect of the buffer head cap are explored,and the large-scale model high-speed water entry impact test is carried out,The test data are filtered according to the natural frequency of the second-order bending mode in the dry modal analysis of the vehicle model.The results show that in the range studied in this paper,the layered buffer shows a stronger impact energy absorption effect than the non layered buffer,and the impact energy absorbed by the buffer increases with the increase of the number of layers;The buffer with negative density gradient is better than that with positive density gradient;The greater the density difference between layers,the greater the loss of impact energy,and the better the load reduction effect of buffer head cap.

关 键 词：高速入水 缓冲降载 梯度密度 ALE 算法 能量吸收 

分 类 号：TB126[理学—工程力学]