High-speed photographic study on overdriven detonation of high explosive

2001 ◽  
Author(s):  
Zhi-Yue Liu ◽  
Shiro Kubota ◽  
Shirou Nagano ◽  
Shigeru Itoh
Keyword(s):  
High Speed ◽  
High Explosive ◽  
Overdriven Detonation

Research on Shockwave Propagation in Hydrogen

2007 ◽  
Author(s):  
Masayuki Murakami ◽  
Yosuke Hemuki ◽  
Shigeru Itoh
Keyword(s):  
High Speed ◽  
High Explosive ◽  
High Speed Camera ◽  
Graph Method ◽  
Camera Image

This paper deals with the propagation of a shockwave in the hydrogen vessel. The aim of this research is the improvement of safety to store hydrogen. The shockwave is generated by the high explosive of the proper quantity and is controlled by a PMMA card gap. The shockwave propagation is visualized by using a high-speed camera image and movie. Shooting procedure is by a shadow graph method. We succeeded in photography of shockwave propagation and combustion phenomenon. Results are then compared with other medium.

scholarly journals High Speed, Localized Multi-Point Strain Measurements on a Containment Vessel at 1.7 MHz Using Swept-Wavelength Laser-Interrogated Fiber Bragg Gratings

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5935
Author(s):  
Steve Gilbertson ◽  
Mark Pickrell ◽  
Dario Castano ◽  
Gary Salazar ◽  
Tom Beery ◽  
...  
Keyword(s):  
Strain Measurement ◽  
High Speed ◽  
High Explosive ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Laser Source ◽  
Global Changes ◽  
Element Analysis ◽  
All Optical ◽  
Explosive Detonation

Dynamic elastic strain in ~1.8 and 1.0 m diameter containment vessels containing a high explosive detonation was measured using an array of fiber Bragg gratings. The all-optical method, called real-time localized strain measurement, recorded the strain for 10 ms after detonation with additional measurements being sequentially made at a rate of 1.7 MHz. A swept wavelength laser source provided the repetition rate necessary for such high-speed measurements while also providing enough signal strength and bandwidth to simultaneously measure 8 or more unique points on the vessel’s surface. The data presented here arethen compared with additional diagnostics consisting of a fast spectral interferometer and an optical backscatter reflectometer to show a comparison between the local and global changes in the vessel strain, both dynamically and statically to further characterize the performance of the localized strain measurement. The results are also compared with electrical resistive strain gauges and finite element analysis simulations.

The Performance of Pressure Vessel Using Concentric Double Cylindrical High Explosive

2004 ◽  
Vol 126 (4) ◽  
pp. 409-413 ◽  
Author(s):  
Toru Hamada ◽  
Yuichi Nakamura ◽  
Shigeru Itoh
Keyword(s):  
High Velocity ◽  
High Explosive ◽  
Maximum Pressure ◽  
Detonation Pressure ◽  
Low Velocity ◽  
High Explosives ◽  
Detonation Process ◽  
Set Up ◽  
Overdriven Detonation ◽  
Detonation Phenomenon

The detonation pressure from the steady detonation of high explosives is a characteristic. Nevertheless, in materials processing using high explosives, there are cases when the detonation pressure does not match the intended pressure. In this investigation, as a new method of generating the overdriven detonation effectively, a double cylindrical high explosive set up using two kinds of explosives was developed, and its basic performance is analyzed. The concentric double cylindrical high explosive set up was composed of a high velocity explosive and a low velocity explosive, and the overdriven detonation was performed in the low velocity explosive. In this experiment, the ion gap was set up in the high velocity explosive and low velocity explosive respectively, and the detonation velocity was measured. The detonation pressure was also measured by setting up a manganin gauge (Kyowa Electric Instrument Co., Ltd.,) at the position where the generation of the overdriven detonation phenomenon was expected. Furthermore, the overdriven detonation process of the concentric double cylindrical high explosive was continually observed by numerical analysis and the framing photography. From the experimental results, the very high pressure region including the mach stem was observed in the low velocity explosive, and the overdriven detonation phenomenon was confirmed. The maximum pressure value of the concentric double cylindrical high explosive set up was 2.3 times higher than the Chapman-Jouguet pressure of the single explosive.

Behaviors of High Explosive near the Critical Conditions for Shock Initiation of Detonation

2007 ◽  
Vol 566 ◽  
pp. 15-22 ◽  
Author(s):  
Shiro Kubota ◽  
Yuji Ogata ◽  
Yuji Wada ◽  
Tei Saburi ◽  
Kunihito Nagayama
Keyword(s):  
Shock Front ◽  
High Speed ◽  
High Explosive ◽  
Critical Conditions ◽  
High Speed Photography ◽  
Shock Initiation ◽  
Donor And Acceptor ◽  
Inner Diameter ◽  
Detonation Transition ◽  
Reaction Wave

The behaviors of the high explosive near the critical conditions for shock initiation of detonation are investigated by high speed photography and pressure measurements in gap tests. The sample is RDX base explosive, and the inner diameter of donor and acceptor charges is 26 mm. Gap material is PMMA. Near the critical condition, the results under the following conditions have been discussed. 1) Shock to detonation transition (SDT) take place in acceptor, 2) The SDT does not occur, but the reaction wave affects the leading shock front in acceptor, and 3) The gap length in which the effect of the reaction wave to shock front almost disappears. These results are very useful to construct the initiation model for solid explosive.

On Study of Free Metal Forming Using Underwater Shock Wave

2002 ◽  
Author(s):  
Shigeru Itoh ◽  
Hirofumi Iyama ◽  
K. Raghukandan ◽  
Shiro Nagano ◽  
Ryo Matsumura ◽  
...  
Keyword(s):  
Shock Wave ◽  
High Explosive ◽  
Dynamic Pressure ◽  
Powder Materials ◽  
Underwater Shock Wave ◽  
Powder Consolidation ◽  
Underwater Shock ◽  
Overdriven Detonation ◽  
The Given ◽  
Basic Configuration

In the material processing such as shock synthesis and powder consolidation by shock waves the method for generating dynamic pressure is of very importance for the final recovered materials. A general and convenient way for producing shock wave needed in such field is to take advantage of the explosion effect from high explosive. Therefore, it becomes an interest subject how to produce dynamic pressure as high as possible under the given high explosive. Starting from this motivation, we put forward a method of high-pressure generation by using the overdriven detonation of high explosive. The basic configuration for this device is summarized in the following. A metal flyer accelerated by the high explosive is used to impact another layer of high explosive to incur an overdriven detonation in this layer of explosive. The overdriven detonation of high explosive acts on the powder materials, providing the high dynamic pressure for it. To examine the efficiency of this combination, a numerical computation is performed to this system. The details on the illustration of this system and numerical treatment will be given.

VISUALIZATION OF AN OVERDRIVEN DETONATION PHENOMENON IN A HIGH EXPLOSIVE

1999 ◽  
Vol 6 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Shigeru Itoh ◽  
Zhi-yue Liu ◽  
Shiro Nagano ◽  
Hiroshi Kitaki
Keyword(s):  
High Explosive ◽  
Overdriven Detonation ◽  
Detonation Phenomenon
Sign in / Sign up

Export Citation Format

Share Document