Dynamic Responses of a Cylindrical Shell Subjected to Shock Wave Induced by Underwater Explosion

1997 ◽  
Author(s):  
Zhong Weifang ◽  
Liu Zhongzu
Keyword(s):  
Shock Wave ◽  
Cylindrical Shell ◽  
Underwater Explosion ◽  
Dynamic Responses ◽  
Equilibrium Equations ◽  
Wave Pressure ◽  
Coupled Equations ◽  
Shock Wave Pressure ◽  
Wave Induced ◽  
Interaction Problem

Abstract The dynamic responses of a finite length cylindrical shell submerged in an infinite, inviscid, irrotational, incompressible fluid and subjected to shock waves induced to underwater explosion due to a spherical charge, are investigated in the view of method of modal superposition. Effects of shock wave pressure and hydrodynamic force are considered in shell equilibrium equations. By expanding distribution function of shock wave pressure into Fourier series and using method of Galerkin, the coupled equations of fluid-structure interaction problem are solved numerically. Finally, displacement re sponse of the shell is obtained.

scholarly journals A Lab-Scale Experiment Approach to the Measurement of Wall Pressure from Near-Field under Water Explosions by a Hopkinson Bar

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xiongwei Cui ◽  
Xiongliang Yao ◽  
Yingyu Chen
Keyword(s):  
Shock Wave ◽  
Near Field ◽  
Underwater Explosion ◽  
Experimental System ◽  
Hopkinson Bar ◽  
Wall Pressure ◽  
Pressure Loading ◽  
Target Plate ◽  
Wave Pressure ◽  
Shock Wave Pressure

Direct measurement of the wall pressure loading subjected to the near-field underwater explosion is of great difficulty. In this article, an improved methodology and a lab-scale experimental system are proposed and manufactured to assess the wall pressure loading. In the methodology, a Hopkinson bar (HPB), used as the sensing element, is inserted through the hole drilled on the target plate and the bar’s end face lies flush with the loaded face of the target plate to detect and record the pressure loading. Furthermore, two improvements have been made on this methodology to measure the wall pressure loading from a near-field underwater explosion. The first one is some waterproof units added to make it suitable for the underwater environment. The second one is a hard rubber cylinder placed at the distal end, and a pair of ropes taped on the HPB is used to pull the HPB against the cylinder hard to ensure the HPB’s end face flushes with loaded face of the target plate during the bubble collapse. To validate the pressure measurement technique based on the HPB, an underwater explosion between two parallelly mounted circular target plates is used as the validating system. Based on the assumption that the shock wave pressure profiles at the two points on the two plates which are symmetrical to each other about the middle plane of symmetry are the same, it was found that the pressure obtained by the HPB was in excellent agreement with pressure transducer measurements, thus validating the proposed technique. To verify the capability of this improved methodology and experimental system, a series of minicharge underwater explosion experiments are conducted. From the recorded pressure-time profiles coupled with the underwater explosion evolution images captured by the HSV camera, the shock wave pressure loading and bubble-jet pressure loadings are captured in detail at 5  mm, 10  mm, …, 30  mm stand-off distances. Part of the pressure loading of the experiment at 35  mm stand-off distance is recorded, which is still of great help and significance for engineers. Especially, the peak pressure of the shock wave is captured.

Relation between Actual Mass and Simulation Mass of Far-Field Underwater Explosion

2011 ◽  
Vol 127 ◽  
pp. 350-354
Author(s):  
Zui Wei Xie ◽  
Xin Yue Wu ◽  
Qiang Wan
Keyword(s):  
Shock Wave ◽  
Curve Fitting ◽  
Underwater Explosion ◽  
Far Field ◽  
Rapid Decay ◽  
Wave Pressure ◽  
Empirical Results ◽  
Shock Wave Pressure ◽  
Simulation Results ◽  
Actual Mass

The far-filed underwater explosive shock wave pressure and impulse is simulated by the FEM code LS-DYNA, and the simulation results are found having rapid decay characteristic through compared with the empirical results. Based on this phenomenon, the relations, whose validity is verified through a computation instance, between simulation mass and actual mass under given initial conditional is obtained by using curve fitting. Using those equations, the accuracy of LS-DYNA to simulate far-field underwater explosive can significantly be increased, thus the ability of this code to simulate far-field underwater explosion is enhanced.

Research on Response of Copper to Micro Laser Shock Peening under 2-D Pressure Model

2013 ◽  
Vol 568 ◽  
pp. 37-43
Author(s):  
Yu Jie Fan ◽  
Kai Ting Yin ◽  
Yong Mei Zhu
Keyword(s):  
Shock Wave ◽  
Radial Direction ◽  
Pressure Effect ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Wave Pressure ◽  
Shock Wave Pressure ◽  
Shock Peening ◽  
Microscale Simulations ◽  
Wave Induced

2-D pressure model in axial and radial direction was proposed to simulate response of copper subjected to micro laser shock peening (μLSP) according to the size effect in the propagation of shock wave induced by laser in microscale. Simulations under 1-D and 2-D pressure model were conducted respectively in order to explore the effect of pressure in radial direction. The results show that distribution of residual stress and plastic deformation in depth and width are obviously different, and response of copper under 2-D pressure model are more close to the experimental results. The pressure effect in radial direction in the propagation of shock wave shouldnt be ignored, and 2-D shock wave pressure model plays an important role in accurate simulation of μLSP.

Influence of a shock-wave pressure gradient on the appearance of a microhardness maximum in α-Fe irradiated by a high-power ion beam

1998 ◽  
Vol 24 (10) ◽  
pp. 819-821 ◽  
Author(s):  
A. N. Valyaev ◽  
A. D. Pogrebnyak ◽  
S. N. Bratushka ◽  
V. I. Lavrent’ev ◽  
S. N. Volkov ◽  
...  
Keyword(s):  
Shock Wave ◽  
Pressure Gradient ◽  
High Power ◽  
Ion Beam ◽  
Wave Pressure ◽  
Shock Wave Pressure

Effects of the aluminum content on the shock wave pressure and the acceleration ability of RDX-based aluminized explosives

2014 ◽  
Vol 116 (14) ◽  
pp. 144906 ◽  
Author(s):  
Z. Q. Zhou ◽  
J. X. Nie ◽  
Z. C. Ou ◽  
J. F. Qin ◽  
Q. J. Jiao
Keyword(s):  
Shock Wave ◽  
Aluminum Content ◽  
Wave Pressure ◽  
Acceleration Ability ◽  
Shock Wave Pressure

Experimental Study on Deformation and Shock Damage of Cylindrical Shell Structures Subjected to Underwater Explosion

2010 ◽  
Vol 224 (11) ◽  
pp. 2505-2514 ◽  
Author(s):  
L-J Li ◽  
W-K Jiang ◽  
Y-H Ai
Keyword(s):  
Cylindrical Shell ◽  
Underwater Explosion ◽  
Experimental Results ◽  
Dynamic Responses ◽  
Shell Structures ◽  
Security Evaluation ◽  
Wave Loading ◽  
Shell Models ◽  
Edge Cracks ◽  
Damage Condition

The security evaluation of some structures shocked by an underwater explosion (UNDEX) frequently plays a key role in some cases, and it is necessary to accurately predict the damage condition of the structure in an UNDEX environment. This study investigates the dynamic linear and non-linear responses and shock damages of two kinds of submerged cylindrical shell models exposed to underwater spherical trinitrotoluene (TNT) charge explosions in a circular lake. Two endplates and a middle plate are mounted on the cylindrical shells to provide support and to create two enclosed spaces. The two kinds of cylindrical shell models with the same geometry characteristics are unfilled and main hull sand-filled. Fifteen different tests are carried out by changing the TNT explosive weights of 1 and 2 kg, standoff distances ranging from 3 to 0.3 m, and two explosion positions. Measured experimental results are compared with each other, and some transformed data are obtained. A detailed discussion on experimental results shows that the dynamic responses and damage modes are much different, and the main hull sand-filled cylindrical shell is more difficult to be damaged by the shock wave loading than the unfilled model. Edge cracks are mainly observed at the instrument hull of the main hull sand-filled model, but surface tearing and cracks are observed on both the main hull and the instrumental hull of the unfilled model, respectively.

scholarly journals Superconductivity of Mg/MgO interface formed by shock-wave pressure

2013 ◽  
Vol 488 ◽  
pp. 18-24 ◽  
Author(s):  
N.S. Sidorov ◽  
A.V. Palnichenko ◽  
D.V. Shakhrai ◽  
V.V. Avdonin ◽  
O.M. Vyaselev ◽  
...  
Keyword(s):  
Shock Wave ◽  
Wave Pressure ◽  
Shock Wave Pressure
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