scholarly journals Pressure Hull Analysis under Shock Loading

2008 ◽  
Vol 15 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Ya-Jung Lee ◽  
Chia-Hao Hsu ◽  
Chien-Hua Huang
Keyword(s):  
Shock Wave ◽  
Pressure Distribution ◽  
High Performance ◽  
Shock Loading ◽  
Shock Pressure ◽  
Structural Arrangement ◽  
Simulation Efficiency ◽  
Long Run ◽  
Underwater Shock ◽  
Initial Shock

The hull of high performance submarines must resist underwater shock loading due to exploding torpedoes or depth bombs. An underwater shock involving an initial shock wave and successive bubble pulsating waves is so complex that a theoretical technique for deriving shock pressure distribution is required for improving simulation efficiency. Complete shock loading is obtained theoretically in this work, and responses of a submarine pressure hull are calculated using ABAQUS USA (Underwater Shock Analysis) codes. In the long run, this deflection and stress data will assist in examining the structural arrangement of the submarine pressure hull.

Optimal Design of Shock Compaction Device

2007 ◽  
Vol 566 ◽  
pp. 339-344 ◽  
Author(s):  
Young Kook Kim ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Numerical Analysis ◽  
Optimal Design ◽  
Shock Pressure ◽  
Underwater Shock Wave ◽  
Reflected Wave ◽  
Shock Compaction ◽  
Water Container ◽  
Underwater Shock

In order to achieve an optimal design of shock compaction device, various designs of parts are attempted. For the height of water container that creates an underwater shock wave and a reflected wave, a characteristic of underwater shock wave is evaluated by means of numerical analysis. It is found that the underwater shock wave and the reflected wave became one wave with higher shock pressure in the case of water container (height 21.5 mm). Also, the evaluation for a powder container is experimentally tried in consideration of reuse.

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.

A Deburring Process Performed by Underwater Shock Wave

2011 ◽  
Vol 673 ◽  
pp. 271-274 ◽  
Author(s):  
Kazumasa Shiramoto ◽  
Junki Shimizu ◽  
Akiyoshi Kobayashi ◽  
Masahiro Fujita
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Present Report ◽  
Shock Pressure ◽  
Normal Operation ◽  
Underwater Shock Wave ◽  
Water Flows ◽  
Underwater Shock ◽  
Machining Operations ◽  
Equipment Performance

A burr is most commonly created after machining operations, such as drilling. Drilling burrs, for example, are common when drilling almost any material. When burrs are broken during the operation of a machine including the parts with the created burrs, the broken piece is in fear of disturbing normal operation or damaging the parts of the machine, so that the sufficient deburring is requested because it can affect equipment performance, reliability, and durability. Several deburring method have been developed up to date. In the present report, we proposed a deburring method by means of applying underwater shock wave. The method is as follows: after all entrance of holes is closed with seal tape, the equipment is submerged, so that all passages for running fluid are filled with air. The explosive is set under water near the entrance of the main hole. As soon as the explosive is detonated, the underwater shock wave generated at the detonation point arrives at the entrance of the hole and breaks through the tape. The water flows into the hole with a high speed. The burr is broken by water hummer action of high speed. In the present investigation, the experiments of deburring are performed under some setting conditions of explosive. It is found by experimental results, that the burr is sufficiently removed with the newly proposed method. When the shock pressure is sufficiently high at the entrance of hole, the burr is broken surface is smooth as polished one. When the shock pressure is not sufficiently high, the broken surface of the burr is notched.

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.

Numerical Simulation on Manufacturing of Pressure Vessel for Shock Food Processing Using Explosive Forming

2016 ◽  
Author(s):  
Hirofumi Iyama ◽  
Masatoshi Nishi ◽  
Yoshikazu Higa ◽  
Ken Shimojima ◽  
Osamu Higa ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Pressure Distribution ◽  
Pressure Vessel ◽  
Food Processing ◽  
Metal Plate ◽  
Underwater Shock Wave ◽  
Deformation Velocity ◽  
Underwater Shock ◽  
Explosive Forming

The explosive forming is a characteristic forming method. An underwater shock wave is generated by underwater explosion of the explosive. A metal plate is affected high strain rate by the shock loading and is formed along a metal die. Although this method has the advantage of mirroring the shape of the die, a free forming was used in this paper. An expensive metal die is not necessary for this free forming. It is possible that a metal plate is formed with simple supporting parts. However, the forming shape is depend on the shock pressure distribution act on the metal plate. This pressure distribution is able to change by the shape of explosive, a mass of explosive and a shape of pressure vessel. On the other hand, we need the pressure vessel for food processing by the underwater shock wave. Therefore, we propose making the pressure vessel by the explosive forming. One design suggestion of pressure vessel made of stainless steel was considered. However, we cannot decide suitable conditions, the mass of the explosive and the distance between the explosive and the metal plate to make the pressure vessel. In order to decide these conditions, we have tried the numerical simulation of this explosive forming. The basic simulation method was ALE (Arbitrary Laglangian Eulerian) method. Mie-Grümeisen EOS (equation of state), JWL EOS, Johnson-Cook constitutive equation for a material model were applied in the numerical simulation. In this paper, the underwater pressure contours to clear the propagations of the underwater shock wave, forming processes and deformation velocity of the metal plate is shown and it will be discussed about those results.

The Industrial Applications of Underwater Shock Wave

2007 ◽  
Vol 566 ◽  
pp. 361-372 ◽  
Author(s):  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Food Processing ◽  
Shock Loading ◽  
Industrial Applications ◽  
Optical Observations ◽  
Coffee Bean ◽  
Underwater Shock Wave ◽  
Treated Sample ◽  
Underwater Shock ◽  
Electric Discharge In Water

The industrial applications of under shock wave have been investigated in our center. This paper concerns with the improvement of foods and wood using underwater shock wave. Underwater shock wave is easily generated by means of explosion of explosives or high voltage electric discharge in water. A detonating fuse and an electric detonator were used for generation of underwater shock wave, and apples were used as food sample for food processing experiments. The behavior of underwater shock wave was investigated by optical observations. The extraction and the amount of phenolic compounds in apple juice obtained from the shock treated sample were higher than that of control samples. It is considered that the underwater shock wave treatment for apples has a big possibility in food processing. The results of coffee bean and other food processing by underwater shock wave were presented at the conference. Moreover the properties of wood were well improved by shock loading. The resistance of wood has been improved significantly.

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.

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.

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