An Investigation on Underwater Explosive Bonding Process

In this paper, we propose a new explosive bonding method for bonding materials by using the underwater shock wave from the explosion of explosives in water. This method is especially suitable to bond the materials with thin thickness and largely dissimilar property. In bonding those materials, the shock pressure and the moving velocity of shock wave on the flyer plate should be precisely managed to achieve an optimum bonding conditions. In this method, the bonding conditions can be controlled by varying of the space distance between the explosive and the flyer plate or by inclining the explosive charge with the flyer plate. We made the experiment of this technique bond the amorphous film with the steel plate. A satisfactory result was gained. At the same time, numerical analysis was performed to investigate the bonding conditions. The calculated deformation of the flyer plate by the action of underwater shock wave was compared with the experimental recordings by high-speed camera under the same conditions. The comparison shows that the numerical analysis is of good reliability on the prediction of the experimental result. Furthermore, the numerical simulation also gives the deformations of the flyer and the base plate, and the pressure and its variation during the collision process.

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Deformation and Collision Process of Metal Plate on Explosive Welding Using Underwater Shock Wave

Emerging Technologies in Fluids, Structures and Fluid Structure Interactions: Volume 1, Fluid Dynamics, Fluid Structure Interaction, and High Explosive Detonation ◽

10.1115/pvp2002-1465 ◽

2002 ◽

Author(s):

Hirofumi Iyama ◽

Masahiro Fujita ◽

K. Raghukandan ◽

Kazuyuki Hokamoto ◽

Shigeru Itoh

Keyword(s):

Shock Wave ◽

Explosive Welding ◽

Amorphous Film ◽

Simulation Method ◽

Metal Plate ◽

Flyer Plate ◽

Collision Process ◽

Underwater Shock Wave ◽

Underwater Shock ◽

Inclined Angle

Explosive welding using underwater shock wave has been conducted. This technique is a new method of explosive welding and can weld a steel plate with an amorphous film, multi-layer of thin copper plates and so on. The conventional method of usual explosive welding cannot weld these combinations of material. It is possible to change shock pressure acting on the flyer plate easily, because the equipment for this method can change the inclined angle and distance between the explosive and flyer plate. However, we have to understand the mechanism of this method to seek the most suitable for set-up condition. Therefore, the numerical simulation of this method was made. The simulation method was FDM using Lagrangean scheme and it can express the detonation process of explosive, propagation process of underwater shock wave, deformation process of metal plate and collision process of between flyer and base plates. In this paper, these simulation results are discussed.

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Behavior of Bubble in Small Water Tank Used for Food Processing Using Underwater Shock Wave

Materials Science Forum ◽

10.4028/www.scientific.net/msf.673.225 ◽

2011 ◽

Vol 673 ◽

pp. 225-230 ◽

Cited By ~ 1

Author(s):

Hideki Hamashima ◽

Manabu Shibuta ◽

Shigeru Itoh

Keyword(s):

Numerical Simulation ◽

Shock Wave ◽

Food Processing ◽

High Speed ◽

Underwater Explosion ◽

Video Camera ◽

Experimental Result ◽

Water Tank ◽

Underwater Shock Wave ◽

Small Water

The food processing technology using a shock wave can prevent deterioration of the food by heat because it can process food in a short time. Generally, since the shock wave used for food processing is generated by underwater explosion, the load of a shock wave to the food becomes very complicated. Therefore, in order to process safely, it is important to clarify the behaviors of the shock wave and the bubble pulse generated by underwater explosion. In this research, in order to investigate the behavior of the shock wave in the water tank used for food processing, the optical observation experiment and the numerical simulation were performed. In the experiment, the shock wave generated by underwater explosion was observed with the high-speed video camera. The numerical simulation about the behavior of bubble pulse was performed using analysis software LS-DYNA. Comparing and examining were performed about the experimental result and the numerical simulation result. The result of the numerical simulation about the behavior of the shock wave generated by underwater explosion and the shock wave generated by the bubble pulse and the bubble pulse was well in agreement with the experimental result.

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A Study of Developing Composite Material of Penetrated Diamond Particles Into Metal Plate

Volume 5: High Pressure Technology; Nondestructive Evaluation Division; Student Paper Competition ◽

10.1115/pvp2009-77593 ◽

2009 ◽

Author(s):

Keijiro Nishi ◽

Shigeru Tanaka ◽

Shigeru Itoh

Keyword(s):

Thermal Conductivity ◽

Shock Wave ◽

Composite Material ◽

High Speed ◽

High Hardness ◽

Optical Microscope ◽

Metal Plate ◽

Underwater Shock Wave ◽

Diamond Particles ◽

Underwater Shock

An explosive welding technique which uses underwater shock wave to weld thin aluminum plate has been studied and the technical advantages were reported. In this research, we propose a method to produce a composite material using an underwater shock wave generated by detonation of explosive. In the production process, a metal plate (flyer plate) accelerates to a high speed by the underwater shock wave, and collided with diamond particles and penetrated the metal plate. Diamonds were used as the particles and aluminum plates (A1050) as the flyer plates. Diamond has high hardness and excellent thermal conductivity, therefore diamond should provide improvement in the thermal conductivity of the composite material. From recovered sample, the multilayer joined surface including diamond particles was observed using an optical microscope. The production of the pipe of composite materials was attempted using this technique as the application. Details of the experimental methods and results are reported in this paper.

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New Technique for “Cullet” Generation of Glass Bottles by Using Underwater Shockwave

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.326-328.1551 ◽

2006 ◽

Vol 326-328 ◽

pp. 1551-1554

Author(s):

Hidetoshi Sakamoto ◽

Shinjiro Kawabe ◽

Kazuo Satoh ◽

Masahiro Himeno ◽

Shigeru Itoh

Keyword(s):

Shock Wave ◽

High Speed ◽

Fracture Process ◽

Image Converter ◽

Glass Bottle ◽

Underwater Shock Wave ◽

Application Technique ◽

System A ◽

Underwater Shock ◽

Glass Bottles

As the application technique for glass bottle’s recycling system, a new “Cullet” generation method by using underwater shock wave was proposed. This small fragmentation technique of glass bottles has a lot of excellent advantages such as the simplification of process by simultaneous cleaning and crushing operation, the high collect rate of “Cullet” and so on. In this study, the relation between of the explosive conditions and “Cullet” sizes were clarified and the high speed fracture process of glass bottle was observed by framing photograph of high speed image converter.

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Exfoliation of Marine Organisms Technology by Using Underwater Shock Wave

Volume 4: Fluid Structure Interaction ◽

10.1115/pvp2005-71437 ◽

2005 ◽

Author(s):

Toshiaki Watanabe ◽

Hirofumi Iyama ◽

Ayumi Takemoto ◽

Shigeru Itoh

Keyword(s):

Shock Wave ◽

High Speed ◽

Marine Organisms ◽

High Speed Camera ◽

Sluice Gate ◽

Underwater Shock Wave ◽

Manual Operation ◽

Fluid Resistance ◽

Personnel Expenses ◽

Underwater Shock

Adhesion problem of marine organisms often becomes a problem, in the case of ship, marine floating construction and sluice gate of power plant. These make fluid resistance of a hull increase, cause a buoyancy fall, or cause reducing coolant etc. Although these are chiefly removed by manual operation now, immense expense and immense labors, such as personnel expenses and time and effort, are needed. We tried application of an underwater shock wave, in order to solve these problems. Interference of a shock wave and the mechanism of marine organisms exfoliation were explored using the explosive and PMMA plate, which imitated a marine organisms adhesion. The process of exfoliation of organisms from PMMA plate was observed by using of the high-speed camera.

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Optimal Design of Shock Compaction Device

Materials Science Forum ◽

10.4028/www.scientific.net/msf.566.339 ◽

2007 ◽

Vol 566 ◽

pp. 339-344 ◽

Cited By ~ 2

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.

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Basic Study on the Crushing of Frozen Soil by Shock Loading

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2007-26430 ◽

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.

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