Destruction of Concrete Block Using Underwater Shock Wave Generated by Electric Discharge

2006 ◽  
Author(s):  
Masahiko Otsuka ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Electric Discharge ◽  
High Voltage ◽  
High Speed ◽  
Concrete Block ◽  
Metal Wire ◽  
High Speed Camera ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
Made In

In this study, the destruction of concrete block using underwater shock wave generated by electric discharge was studied. Initially, the shock wave generated by electric discharge was investigated by optical observation using a high-speed camera and pressure measurement. A comparison of the underwater shock wave generated from the electrode with and without connecting a metal wire was made. A metal wire was connected to an electrode and a high voltage impulsive current was passed through it to generate the underwater shock wave. A hole was made in the concrete block, filled with water and an electrode was inserted into the hole, which acts as a pressure vessel. The electric current was passed through this electrode to generate underwater shock wave for the destruction of concrete block.

A Study on Shock Energy for Concrete Destruction Using Underwater Shock Wave

2007 ◽  
Vol 566 ◽  
pp. 225-230 ◽  
Author(s):  
Masahiko Otsuka ◽  
Naoki Okamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Peak Pressure ◽  
Concrete Block ◽  
Metal Vapor ◽  
Metal Wire ◽  
Underwater Shock Wave ◽  
Long Duration ◽  
Discharge Duration ◽  
Underwater Shock

In this study, the destruction of concrete block using underwater shock wave generated by high current is studied. A metal wire was connected to an electrode and a high voltage impulsive current was passed through it to generate the underwater shock wave. The underwater shock wave was investigated by optical observation using a high-speed camera and pressure measurement. A comparison was made on the shock wave generated from the electrode with and without connecting it to a metal wire. The underwater shock wave generated from electrode without metal wire showed the existence of many shock waves by continuous plasma within discharge duration, and the duration of the pressure pulse was long in this case. The peak pressure of underwater shock wave generated from metal wire explosion was higher than the previous case due to the reaction of metal vapor and water, whereas the pressure duration was less. The concrete block was efficiently destructed by the effect of underwater shock pressure of high impulse. The high peak pressure and long duration are necessary for the destruction of concrete block. It is suggested that high pressure induces crack to the structure, and the long pulse duration destructs the structure.

Exfoliation of Marine Organisms Technology by Using Underwater Shock Wave

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.

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.

Research on the Underwater Shock Wave Generated by Discharge of High Voltage Impulsive Current

2005 ◽  
Author(s):  
Masahiko Otsuka ◽  
Kouhei Inoue ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Voltage ◽  
High Energy ◽  
Resistance Rate ◽  
Pulsed Power ◽  
Metal Wire ◽  
Underwater Shock Wave ◽  
Wire Explosion ◽  
Underwater Shock ◽  
Velocity Pressure

The high energy generated from electric pulsed power has various applications. We investigated the underwater shock wave generated by the metal wire explosion and the electric discharge of electrode using high voltage impulsive current. This investigation was performed using optical observation, pressure measurement and current measurement. In the case of metal wire explosion, the velocity, pressure and the current value of underwater shock wave obtained from the experimental data is proportional to the electric resistance rate. In the other case, the discharge from the electrode, the velocity of the underwater shock wave generated by the discharge of electrode with metal wire explosion is faster than the underwater shock wave generated by the discharge of the electrode without metal wire.

Experimental Study of the Underwater Shock Wave on the High-Voltage Electric Discharge by Carbon Fiber

2013 ◽  
Vol 767 ◽  
pp. 261-264
Author(s):  
Hironori Maehara ◽  
Shigeru Tanaka ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Experimental Study ◽  
Carbon Fiber ◽  
Thin Plate ◽  
Electric Discharge ◽  
High Voltage ◽  
High Capacity ◽  
Underwater Shock Wave ◽  
Underwater Shock

Carbon fiber is employed to induce underwater shock wave by the high-voltage electric discharge. By the release of an energy 10 kJ stored in a high-capacity condenser bank, carbon fiber was exploded showing the evidence inducing underwater shock wave effectively to a thin plate to be formed.

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

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.

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

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.

scholarly journals The Basic Research for Pulverization of Rice Using Underwater Shock Wave by Electric Discharge

2011 ◽  
Vol 5 (2) ◽  
pp. 115-130 ◽  
Author(s):  
Makoto Ide ◽  
Manabu Shibuta ◽  
Naoyuki Wada ◽  
Shigeru Tanaka ◽  
Hideki Hamashima ◽  
...  
Keyword(s):  
Shock Wave ◽  
Electric Discharge ◽  
Basic Research ◽  
Underwater Shock Wave ◽  
Underwater Shock

Research About Pulverization of Rice Using Underwater Shock Wave by Electric Discharge

2010 ◽  
Author(s):  
Makoto Ide ◽  
Seiichi Irie ◽  
Nobuyuki Matsuo ◽  
Asuka Oda ◽  
Shigeru Tanaka ◽  
...  
Keyword(s):  
Shock Wave ◽  
Electric Discharge ◽  
Food Samples ◽  
Frictional Heat ◽  
Underwater Shock Wave ◽  
Manufacturing Method ◽  
Application Techniques ◽  
Rate Improvement ◽  
Underwater Shock ◽  
Rice Powder

In recent years, it is expected that the consumption of rice powder in Japan increases for food self-support rate improvement. The consumption of enormous energy during making rice powder and loss of starch in rice by frictional heat is occurred by using the existing manufacturing method. Application techniques using underwater shock wave which is generated by high voltage electric discharge are studied in our laboratory. When some food samples are treated by underwater shock wave, following advantages are obtained, a little heat treatment, decreasing consumption of the energy, and shortening of processing time. In food processing using underwater shock wave, the spalling destruction due to propagation characteristics of shock wave and mediums, which have difference density, is used. In this study, the pressure vessel for pulverization of rice was developed, and then, intensity of pressure in vessel is measured by way of experiment, and simulated numerical analysis.

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