﻿ 聚脲涂覆铝板水下冲击特性数值模拟研究
 舰船科学技术  2022, Vol. 44 Issue (15): 20-25    DOI: 10.3404/j.issn.1672-7649.2022.15.005 PDF

1. 海军研究院，北京 100161;
2. 北京理工大学 爆炸科学与技术国家重点实验室，北京 100081

Numerical investigation of polyurea coated aluminum plate response subjected to underwater impact
YANG Kun1, ZHANG Wei1, LI Ying2, CHEN Zi-hao2
1. Naval Research Institute, Beijing 100161, China;
2. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
Abstract: The close underwater explosion is difficult for ship explosion protection, and polyurea coating with strain rate strengthening effect provides a new idea for underwater impact protection. Based on the non-explosive underwater impact loading method, the high-strength underwater impact load was applied to the polyurea coated circular aluminum plate target by numerical simulation method. The deformation process of the target under underwater impact was described. The effects of the initial peak value of shock wave and the thickness and position of polyurea coating on the deformation of 6061 aluminum alloy circular plate were discussed. The resistance to underwater impact is measured by the final deformation value of polyurea coated aluminum plate. With the increase of strain rate, the resistance to the underwater impact of the polyurea coated aluminum plate increases, and the resistance to the underwater impact of polyurea coated aluminum plate is the best. The relevant conclusions can provide guidance for the anti underwater impact design of ships and marine structures.
Key words: polyurea     underwater impact     dynamic response     numerical simulation
0 引　言

1 数值模拟方法与有效性验证 1.1 数值模拟方法

 $P\left( t \right) = {P_0}{e^{ - \tfrac{t}{\theta }}}。$ (1)

 ${P_0} = {c_w}{\rho _w}{v_0} ，$ (2)
 $\theta = \frac{{{m_p}}}{{{\rho _w}{c_w}}} 。$ (3)

 ${I_0} = 2\int_0^\infty {{P_0}} {e^{ - \tfrac{t}{\theta }}}{\rm{d}}t = 2{P_0}\theta ，$ (4)

 $\frac{{{\tau _c}}}{\theta } = \frac{1}{{\psi - 1}}\ln \psi 。$ (5)

 $\psi = \frac{{{\rho _w}{c_w}\theta }}{{{m_f}}} 。$ (6)

 ${I_{trans}} = {I_0}{\psi ^{\frac{\psi }{{1 - \psi }}}} ，$ (7)

 $\bar I = \frac{{{I_0}}}{{{\rho _w}{c_w}\sqrt A }} ，$ (8)
 $\bar \delta = \frac{\delta }{R} ，$ (9)
 $\bar h = \frac{h}{R} 。$ (10)

 图 1 基本原理图 Fig. 1 The basic schematic diagram
1.2 数值模拟方法的验证 1.2.1 有限元模型与参数设置

 图 2 有限元模型 Fig. 2 Finite element model

 $\begin{split} \psi =& {C_{10}}\left( {\overline {{l_1}} - 3} \right) + {C_{01}}\left( {\overline {{l_2}} - 3} \right) + {C_{11}}\left( {\overline {{l_1}} - 3} \right)\left( {\overline {{l_2}} - 3} \right) +\\ &{C_{20}}{\left( {\overline {{l_1}} - 3} \right)^2} + {C_{02}}{\left( {\overline {{l_2}} - 3} \right)^2} + \frac{1}{{{C_{30}}}}{\left( {J - 1} \right)^2} 。\end{split}$ (11)

1.2.2 有效性验证

 图 3 数值仿真和试验得到测点A处P-t曲线 Fig. 3 The P-t curve of shock wave at measuring point A obtained by numerical simulation and experiment
2 结果与分析 2.1 聚脲涂覆铝板变形过程

 图 4 数值仿真得到的铝板的动态变形过程 Fig. 4 The dynamic elastic-plastic deformation process of aluminum plate obtained by numerical simulation

 图 5 聚脲敷设铝板在水下冲击波载荷作用下的变形过程剖面图(ms) Fig. 5 Profile of deformation process of polyurea laid aluminum plate under underwater shock wave load (ms)
2.2 参数影响分析

2.2.1 冲击波强度影响

 图 6 不同压力峰值的水下冲击波作用下聚脲敷设铝板中心位移峰值 Fig. 6 Peak value of center displacement of polyurea laid aluminum plate under underwater shock wave with different pressure peaks
2.2.2 聚脲敷设厚度的影响

 图 7 不同聚脲厚度时聚脲敷设铝板中心位移峰值 Fig. 7 Peak value of central displacement of polyurea laid aluminum plate with different polyurea thickness
2.2.3 聚脲敷设位置的影响

 图 8 不同聚脲位置时聚脲敷设铝板中心位移峰值 Fig. 8 Peak value of central displacement of polyurea laying aluminum plate at different polyurea positions
3 结　语

1）在聚脲涂覆铝板塑性变形范围内，聚脲涂层对铝板的抗冲击性能提升与水下爆炸冲击波初始峰值强度呈正比例关系；

2）在受到典型载荷的水下爆炸冲击波作用时，在一定范围内，增加聚脲涂覆厚度可有效降低聚脲涂覆铝板最终大塑性变形值；

3）在受到典型载荷的水下爆炸冲击波作用时，相同厚度的聚脲涂覆在迎爆面时聚脲涂覆铝板最终大塑性变形值最小，将聚脲分成两部分涂覆在铝板的前后的效果最差。

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