The Influence of Flyer Momentum on an Aluminium Plate’s Response to Underwater Shock Loading

2018 ◽  
Vol 35 (02) ◽  
pp. 267-278
Author(s):  
X. He ◽  
J. L. Rong ◽  
D. L. Xiang ◽  
H. Y. Wei ◽  
C. H. Hu ◽  
...  
Keyword(s):  
Shock Waves ◽  
Shock Loading ◽  
Specific Impulse ◽  
Underwater Explosion ◽  
Theoretical Data ◽  
Experimental Results ◽  
Experimental Device ◽  
Simulation Accuracy ◽  
Underwater Shock

ABSTRACTAn underwater shock loading experimental device is used to simulate underwater explosion shock waves. The aim of this study is to investigate the influence of flyer momentum on the response of an aluminium plate to this underwater shock loading experimental device. The simulation accuracy can be verified by comparing theoretical data with the simulation and experimental results. Through simulations, an aluminium plate’s deformation and pressure specific impulse can be determined when flyers impact the piston at different velocities but at the same momentum. The aluminium plate's deformation and pressure specific impulse are constant when the flyers had constant momentum because both are directly proportional to the flyer momentum. The results have an important practical value for understanding and using this type of experimental device.

A COMPARATIVE DAMAGE STUDY OF AIR- AND WATER-BACKED PLATES SUBJECTED TO NON-CONTACT UNDERWATER EXPLOSION

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1311-1318 ◽  
Author(s):  
R. RAJENDRAN ◽  
J. M. LEE
Keyword(s):  
Damage Assessment ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Ship Design ◽  
Experimental Results ◽  
Underwater Shock ◽  
Motivating Factor ◽  
Damage Study ◽  
Side Shell

The response of the side shell to non-contact underwater explosion is of major concern in ship design. While extensive research is carried out on air-backed plates, relatively less attention is paid to water-backed plates. Nevertheless, the response of the water-backed plates becomes relevant when the water filled side shells are exposed to an underwater shock loading. Availability of scant information on the experimental results of water-backed plates is the primary motivating factor to make analytical estimates. These estimates are provided in comparison with an air-backed plate for identical attack geometry and target parameters. This work aims to bring out a comparative procedure for the damage assessment between air- and water-backed plates so that the response of the latter can be presented in terms of that of the former.

Basic Study on the Crushing of Frozen Soil by Shock Loading

2007 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Hironori Maehara ◽  
Masahiko Otsuka ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Frozen Soil ◽  
High Speed Camera ◽  
Underwater Shock Wave ◽  
Basic Study ◽  
Underwater Shock ◽  
A New Technique

The aim of study is to confirm a new technique that can crush the frozen soil and/or ice block using underwater shock wave generated by the underwater explosion of explosive. This technique can lead to the earlier sowing, which can have the larger harvest because the duration of sunshine increases. Especially, in Hokkaido prefecture, Japan, if the sowing is carried out in April, we can expect to have 150% of harvest in the ordinary season. This technique is effective against the cold regions. For example, Korea, China, Mongolia, Russia, Norway, and Sweden, etc. At first, we carried out experiments usung a detonating fuse and ice block. The process of ice breaking was observed by means of a high-speed camera. In order to check about that influence we tried to give an actual frozen soil a shock wave.

An Investigation on the Properties of Underwater Shock Waves Generated in Underwater Explosions of High Explosives

1997 ◽  
Vol 119 (4) ◽  
pp. 498-502 ◽  
Author(s):  
S. Itoh ◽  
Z. Liu ◽  
Y. Nadamitsu
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Numerical Simulations ◽  
Underwater Explosion ◽  
High Explosives ◽  
Underwater Shock Wave ◽  
Underwater Explosions ◽  
Expansion Test ◽  
Gas Products ◽  
Underwater Shock

A cylinder expansion test for high explosives was carried out to determine JWL parameters. Using the JWL parameters, we carried out numerical simulations of the underwater shock waves generated by the underwater explosion of the high explosives. Our results showed that the behavior of the underwater shock waves at the vicinity of the explosives differs greatly from that far from the explosives. Especially, the strength of the underwater shock wave nearby the explosive rapidly decreases due to the effect of the expansion of the gas products.

A New Method of Explosive Welding Performed by Effective Application of Reflected Underwater Shock Wave

2006 ◽  
Author(s):  
Kazumasa Shiramoto ◽  
Masahiro Fujita ◽  
Hirofumi Iyama ◽  
Yasuhiro Ujimoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Explosive Welding ◽  
Underwater Explosion ◽  
Shock Pressure ◽  
Experimental Results ◽  
New Method ◽  
Underwater Shock Wave ◽  
Effective Application ◽  
Welding Method ◽  
Underwater Shock

In this report, we propose a new explosive welding method, and the welding is performed at employing underwater shock pressure produced by the underwater explosion of an explosive placed at one side almost vertical to the specimen to be welded. In order to prevent the reduction of the shock pressure with the distance away from explosive, a steel reflector is placed over the area of the specimen. The effects of the reflector are investigated based on the experimental results and the process is numerically analyzed results.

Promotion of Thawing Frozen Soil by Shock Wave Loading

2013 ◽  
Vol 767 ◽  
pp. 205-210
Author(s):  
Toshiaki Watanabe ◽  
Hideki Hamashima ◽  
Hironori Maehara ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Water Layer ◽  
Frozen Soil ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
A New Technique

The aim of study is to confirm a new technique that can crush the frozen soil and/or ice block using underwater shock wave generated by the underwater explosion of explosive. This technique can lead to the earlier sowing, which can have the larger harvest because the duration of sunshine increases. Especially, in Hokkaido prefecture, Japan, if the sowing is carried out in April, we can expect to have 150% of harvest in the ordinary season. This technique is effective against the cold regions, for example, Russia, Norway, and Sweden, etc. In order to check about that influence we tried to give an actual frozen soil a shock wave. We could get a result that existence of water layer serves an important role in promotion of thawing by the shock loading to the frozen soil. That role was confirmed from the result of numerical simulation.

A new effective method to predict the permanent deformation of plane plates subjected to underwater shock loading

2010 ◽  
Vol 225 (5) ◽  
pp. 1069-1075 ◽  
Author(s):  
L-J Li ◽  
W-K Jiang
Keyword(s):  
Shock Loading ◽  
Permanent Deformation ◽  
Underwater Explosion ◽  
Numerical Results ◽  
Gas Bubble ◽  
Computation Efficiency ◽  
Plane Plate ◽  
Underwater Shock ◽  
Structure Domain ◽  
Good Agreement

Theoretical analysis of the shock loading acting on a plane plate is performed for an underwater explosion. An effective new numerical method is used to simulate the plate plastic permanent deformation based on the shock loading acting on the plate. During the numerical simulation, only the structure domain is modelled and gas bubble reloading is ignored, and so computation efficiency is highly improved. The numerical results are modified based on the distribution of shock energy during the underwater explosion, and the modified numerical results are in good agreement with the experimental results.

Numerical Simulation for Development of Pressure Vessel for Food Processing by Shock Loading

2006 ◽  
Author(s):  
Masahiko Otsuka ◽  
Toshiaki Watanabe ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Numerical Analysis ◽  
Pressure Vessel ◽  
Food Processing ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Underwater Shock Wave ◽  
Reflected Wave ◽  
Underwater Shock

In this study, it has aimed at the design of the pressure vessel where an underwater shock wave is applied to food efficiently. This study aims at the desigh of a pressure vessel in which the underwater shock wave generated by the underwater explosion of detonating fuse was experimentally investigated by the optical observation and the pressure measurement. Therefore the pressure vessel is designed so that suitable pressure may apply on food. This designed vessel is evaluated by the numerical analysis that used LS-DYNA3D. The interaction of the underwater shock wave, the incident wave and the reflected wave are investigated by the numerical analysis. The agreement between the experimental results and the numerical analysis was found to be good.

Probabilistic Risk Prediction of Submarine Pipelines Subjected to Underwater Explosion Shock

1999 ◽  
Vol 121 (4) ◽  
pp. 251-254 ◽  
Author(s):  
Z. Zong ◽  
K. Y. Lam ◽  
G. R. Liu
Keyword(s):  
Shock Loading ◽  
Simple Procedure ◽  
Underwater Explosion ◽  
Coupling Model ◽  
Oil Pipeline ◽  
Structure Interaction ◽  
The Monte Carlo Method ◽  
Underwater Shock ◽  
Interaction Problem ◽  
Failure Probabilities

A simple procedure is proposed in this paper to estimate the global failure probabilities of a submarine oil pipeline subjected to underwater explosion shock wave. The deterministic response of a pipeline subjected to an underwater shock loading is first given by solving a simplified fluid-structure interaction problem. Compared with an FEM/BEM coupling model, the present method gives good results at much lower computational efforts. Then, the Monte Carlo method is used to find the global failure probabilities of the pipeline. Finally, a practical example is given.

The Study on the Dynamic Response of Cylindrical Pressure Hull on the Different Shock Loading Empirical Formula

2015 ◽  
Vol 799-800 ◽  
pp. 604-609 ◽  
Author(s):  
Ching Yu Hsu ◽  
Tso Liang Teng ◽  
Cho Chung Liang ◽  
Hai Anh Nguyen ◽  
Chien Jong Shih
Keyword(s):  
Dynamic Response ◽  
Empirical Formula ◽  
Shock Loading ◽  
Failure Modes ◽  
Underwater Explosion ◽  
The Other ◽  
Empirical Formulas ◽  
Underwater Shock ◽  
Simulation Results ◽  
Better Than

This paper focuses on the comparison between underwater explosion (UNDEX) shock loading empirical formulations. First, the numerical simulations for a cylindrical pressure hull subjected to UNDEX loading were conducted and the results are close to the failure modes shown in experiments of Kwon (1993). Second, the empirical UNDEX loading formula of Cole (1948), Keil (1961) and Shin (1994) used in cylinder subjected to underwater shock loading were compared. The simulation results by using three empirical formulas were compared and Shin’s (or Cole’s) empirical formula was shown to be better than the other empirical formulations when subjected to an UNDEX under the same conditions. The analytical results offer a valuable reference to the research of underwater explosion.

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