Papers by Keyword: Explosive

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Authors: Yong Jian Mao, Yu Long Li, Han Jun Huang
Abstract: The cosine-distributed impulsive loads induced by intense soft X-ray radiation are often simulated by explosive rods in laboratory tests. The conventional design method of rods distribution needs a complicated process, by trials or optimization, to ensure the rod number as an integer. This paper proposes a simplified method based on the principle of load discretization and impulse equivalence. It has higher efficiency and more convenience, and can automatically let the rod number be an integer. This study provides an effective design tool for rod-explosive simulation tests of aerospace structures under intense soft X-ray radiation.
Authors: Young Kook Kim, Kazuyuki Hokamoto, Shigeru Itoh
Abstract: A shock compaction method using an underwater shockwave is used to consolidate the Cu/graphite and Ni/graphite composites. The copper powder (particle size < 45 m) and nickel powder (particle size < 150 m) were respectively mixed with the graphite powder (particle size < 45 m, purity 99.9%). The propagation phenomenon of underwater shock wave is studied by means of numerical analysis (LS-DYNA 3D) in terms of the magnitude and distribution of shock pressure impinged on the powder surface. The shock pressure of underwater shock wave obtained from shock compaction device is approximately 16 GPa. To make a big size material (ø30mm), we changed the inner size of powder container from ø10 mm to ø30 mm. We confirmed that the consolidation possibility of the big size composite materials (Cu/graphite, Ni/graphite) by the shock compaction method using underwater shock wave.
Authors: Wen Su Ji, Yu Kui Ding, Yu Qiu Xu
Abstract: The solubility of TNT and RDX was measured in supercritical carbon dioxide fluid at 303.0, 308.0, 323.0, 338.0 K, and over the pressure range from 10.0 MPa to 50.0 MPa. This study examined the influences of extraction temperature, extraction pressure and support effect (SE) between molecules of TNT and RDX on their solubility in the TNT/RDX/SC-CO2 system. The results show that solubility of TNT and RDX in TNT/RDX/SC-CO2 ternary system is much higher than that in binary system. The values of SE of RDX and TNT increase first and decrease then with the pressure changing. The pressure turning point occurred over the pressure range from 25 MPa to 28 MPa for TNT and from 13 MPa to 20 MPa for RDX.
Authors: Wen Ding, Tao Guo, Chong Ji, Rui Qi Shen
Abstract: Oxygen coefficients of 396 explosives, including liquid and solid explosives, 177 dangerous materials, including oxidants, combustible substances, chemical hazards and narcotics, and 9 common packing materials were collected and compared. It can be seem that the explosives can be distinguished from non-explosives by oxygen coefficient with boundary 0.3 to 1.2. This result can support a convincing proof for explosive neutron detection.
Authors: Zachery I. Smith, Edward R. Fyfe, Sean P. Wisotzkey
Abstract: Suspension and cable-stayed bridge cables are currently vulnerable to multiple scenarios that can jeopardize the integrity of the bridge. These can include accidental truck fires and more recently, terrorist attacks. The inherent nature of suspension and cable-stay bridges leaves little redundancy to their structural loads paths. For this reason they are more susceptible to terrorist attacks than possibly any other structure. This paper looks at a composite cable shield composed of various materials each tailored to protect against unique threats. Several test specimens were manufactured by Fyfe Co. LLC and proof tested by the U.S. Army Corps of Engineers. Multiple threat scenarios were simulated by plastic explosives, extreme heat differentials, and various cutting mechanisms. The distinctive prefabricated connections provide for fast installation and a very robust design to prevent cable shield separation under extreme loads. Through the use of several advanced composite materials the cable shields provide a widespread umbrella of protection for potential threats.
Authors: Yoshio Nakayama, Kunihiko Wakabayashi, Tomoharu Matsumura, Mitsuaki Iida
Abstract: To reduce safe distance such as inhabited building distance (IBD), a new type magazine, which is referred to as a subsurface magazine, has been proposed and the explosion effects have been discussed. We have conducted explosive tests by using relatively large scale models (23 kg and 78 kg in mass) and examined mass effect (scale effect) of blast waves caused by explosion of high explosives. The magazines were composed of a arch-type explosive storage room with a line hinge along the top of the roof of the wall, a square passage way to ground which will release the blast wave. Explosion hazards from the explosion of subsurface magazines were collected to understand the characteristics of airblast, fragments, and ground shocks. Safety criteria for the subsurface magazine are discussed based on the experimental results.
Authors: Shiro Kubota, Tei Saburi, Katsumi Katoh, Tomotaka Homae, Yuji Ogata, Mitsuaki Iida
Abstract: The development study of blast containment vessels for anti-terrorism has been conducted. The goal of this study is to develop safe disposal vessel for 10 kg of explosives. Considering of the use at the airport or railroad stations, it needs to be more compact compared with the conventional explosion chamber. By introducing both the internal structure and attenuation technology in the vessel, sufficient blast proof ability to contain internal explosion is realized. The blast containment vessel can be used repeatedly by exchanging the internal structure. To realize these concepts, model experiments were carried out using high speed photography, strain and pressure measurements. By introducing these technologies, the vessel for the 1 kg of explosive materials has been made, and the experiments employing 1 kg C4 explosive have been conducted. Finally, the compact blast containment vessel for 10 kg explosives was made, and its blast proof ability was shown by the internal blast test.
Authors: S. Matsumoto, Y. Nakamura, Shigeru Itoh
Authors: Ganda M. Simangunsong, Shiro Kubota, Tei Saburi, Katsumi Katoh, S. Yoshino, Yuji Wada, Yuji Ogata
Abstract: To design a cylindrically-shape explosion container, the experiment of a high explosive charge detonating in a steel pipe has been performed. The charges, composition C4, were positioned at the geometrical centre of the steel pipe. Two kinds of measurements were performed on the steel pipe: circumferential strain and outside diameter. The strain-time history shows that the pipe structure vibrates and the vibration is decaying. It has been reported that this type of response is explained as the mechanism of strain growth, and this problem is taken up to verify computer simulation in this study. This simulation code could be strong tool to estimate the geometries of the explosion container. The relationship among the pipe parameter, explosive charge and pipe’s final deformation is proposed as practical guidance for predicting radius and thickness of the pipe correspond to the level of internal blast loading.
Authors: Shigeru Tanaka, Greg Kennedy, Kazuyuki Hokamoto, Shigeru Itoh
Abstract: There are few research papers of liner shaped charge (LSC). In this time simplified LSC was made from an explosive and vertically-folded copper plate. In order to confirm a performance of the simplified LSC, steel cutting experiments were conducted by changing distance from the simplified LSC to target steel. Numerical analysis was also conducted by using Ls-dyna. Penetration depth was measured after experiments. Collision velocity of copper was calculated by using Gurnney equation. Numerical simulation model was made by SPH, because large deformation was occurred during collision of copper and steel penetration process. Results from numerical analysis were good correspondence with experimental results. Details are reported on this paper.
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