PERFORMANCE STUDY OF HYBRID BOLTED-BONDED VERTICAL T- AND L-JOINTS WITH COMPOSITE ADHERENDS SUBJECTED TO UNDERWATER SHOCK PRESSURE

2020 ◽  
Vol 61 (4) ◽  
pp. 632-640
Author(s):  
E. Selahi
2007 ◽  
Vol 566 ◽  
pp. 339-344 ◽  
Author(s):  
Young Kook Kim ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh

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.


2008 ◽  
Vol 15 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Ya-Jung Lee ◽  
Chia-Hao Hsu ◽  
Chien-Hua Huang

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.


2011 ◽  
Vol 673 ◽  
pp. 271-274 ◽  
Author(s):  
Kazumasa Shiramoto ◽  
Junki Shimizu ◽  
Akiyoshi Kobayashi ◽  
Masahiro Fujita

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.


1993 ◽  
Vol 101 (1172) ◽  
pp. 445-450
Author(s):  
Ryuichi TOMOSHIGE ◽  
Akira CHIBA ◽  
Minoru NISHIDA ◽  
Kihachiro IMAMURA ◽  
Shigeru ITOH ◽  
...  

Author(s):  
Kazumasa Shiramoto ◽  
Masahiro Fujita ◽  
Hirofumi Iyama ◽  
Yasuhiro Ujimoto ◽  
Shigeru Itoh

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.


1967 ◽  
Vol 29 (2) ◽  
pp. 373-383 ◽  
Author(s):  
A. Coombs ◽  
C. K. Thornhill

A theoretical study is made of a simple design for an underwater shock gun, which consists of a chamber in the form of a hollow circular cone, with a spherical sector of explosive charge fitted into the apex. When the explosive is initiated at the apex, the resulting sector of a spherical blast wave will be diffracted by expansion waves moving inwards after the leading shock has emerged from the rim of the cone.The progress of the expansion wave-fronts is calculated, and the results show a surprising inability of the diffraction process to ‘eat into’ the full-strength sector of spherical blast. It is found to be possible to design such a gun so that it is capable of projecting a high intensity shock-pressure beam over a considerable range, using only a very small explosive charge.


2007 ◽  
Vol 566 ◽  
pp. 345-350 ◽  
Author(s):  
Young Kook Kim ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh

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.


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