scholarly journals Evaluation of anti-explosion performance of Shuibuya concrete-faced rockfill dam slabs subjected to strong shock waves caused by an underwater explosion

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401882220 ◽  
Author(s):  
Lu Lu ◽  
Ye Zhu ◽  
De-Gao Zou ◽  
Qin-Man Fan ◽  
Shao-Bing Dong

A concrete plastic-damage model, the extended Drucker–Prager model for rockfill, and acoustic elements for water were introduced and applied to the impact fracture analysis of a concrete-faced rockfill dam–water three-dimensional system. The plastic-damage dynamic analysis process was used in combination with the concrete compressive and tensile damage model. The 223-m high Shuibuya concrete-faced rockfill dam was analyzed using an explicit integration. Numerical simulations of the damage threshold, rockfill modeling, and interface processing were conducted to research the effect of the anti-explosion performance that occurs when a concrete slab is subjected to an underwater shock wave. The simulation results indicate that the main regions of weakness in the slabs during an underwater shock wave are determined by the tensile damage. The slab’s anti-knock weak areas appear in the right dam abutment and the top of the left dam. The anti-knock performance in the upper slab is inferior to that of the lower slab. Specific local optimization steps should be applied at these locations to improve the slabs’ anti-knock capabilities, which are important for designing concrete-faced rockfill dams.

2018 ◽  
Vol 774 ◽  
pp. 303-306
Author(s):  
Yoshifumi Ohbuchi ◽  
Sota Sugahara ◽  
Shigeru Tanaka ◽  
Shinichi Enoki ◽  
Genj Hotta ◽  
...  

In order to promote the recycling of the one way glass bottles, the impact fracture by using the pulse power underwater shock-wave with micro bubble was examined. It is reported that the pressure of underwater shock-wave with micro-bubble increases. From the experimental result, the glass bottle‘s crushed experiment was executed in the water with micro-bubble. As a result, the small glass fragments (Cullet) increased and it was shown that the micro-bubble in the water promoted the bottle fracture.


2012 ◽  
Vol 152-154 ◽  
pp. 1063-1070 ◽  
Author(s):  
Lu Lu ◽  
Li Xin ◽  
Zhou Jing

To study the effect of a strong underwater shock wave on a concrete dam, in this research the hammers impact were applied to simulate the underwater shock in a model test. The model scale was 200 according to the gravity-elasticity similitude law. Five acceleration sensors were imbedded along the downstream surface of the dam. The maximum input pressure was evaluated based on the recorded accelerations. The explosive charge and the distance between the explosion center and the dam were determined corresponding to the maximum impact pressure. After the hammers impacted, the upstream face of the dam was fractured and downstream was scabbed; some cracks extended from the upstream face to the downstream face; the head of dam was projected; and the dam appeared entirely displacement. Although the damage similarity of the model and prototype is not verified, this method may be used to verify the quality of a protection project and offered evidence to define a protection project.


2011 ◽  
Vol 673 ◽  
pp. 265-270 ◽  
Author(s):  
Akihisa Mori ◽  
Li Qun Ruan ◽  
Kazumasa Shiramoto ◽  
Masahiro Fujita

Detonating code is a flexible code with an explosive core. It is used to transmit the ignition of explosives with high detonation velocity in the range of 5.5 to 7 km/s. However, it is difficult to use detonating code for the explosive welding of common metals since the horizontal point velocity usually exceeds the sound velocity. Hence, in the present work, a new method using underwater shock wave generated by the detonation of detonating code was tried. The details of the experimental parameters and the results are presented. From the results it is observed that the above technique is suitable to weld thin metal plates with relatively less explosives.


1999 ◽  
Vol 85 (1-3) ◽  
pp. 48-51 ◽  
Author(s):  
Y Nadamitsu ◽  
Z.Y Liu ◽  
M Fujita ◽  
S Itoh

2007 ◽  
Vol 566 ◽  
pp. 309-314
Author(s):  
Kazumasa Shiramoto ◽  
Masahiro Fujita ◽  
Yasuhiro Ujimoto ◽  
Hirofumi Iyama ◽  
Shigeru Itoh

The paper describes a numerically simulated result for the explosive welding using reflected underwater shock wave. Through the numerical simulation, the effective use of reflected underwater shock wave was clearly suggested and the method to improve the assembly was demonstrated.


1991 ◽  
Vol 62 (7) ◽  
pp. 1849-1854 ◽  
Author(s):  
Fernando E. Prieto ◽  
Achim M. Loske ◽  
Frederick L. Yarger

2000 ◽  
Author(s):  
S. H. R. Hosseini ◽  
T. Hirano ◽  
O. Onodera ◽  
K. Takayama

Abstract For applying shock waves to precise medical procedures like neurosurgery, a reliable generation of micro shock waves is required. Such sensitive applications make limits on usage of conventional underwater shock wave sources like Extracoporeal Shock Waves ESW [1] or micro explosives [2]. In the present study a Q-switched Ho:YAG laser and an optical fiber are used. Advantages of this method over previous shock wave sources are two order of magnitude reduction in focusing area if compared with ESW and elimination of product gases of micro explosives. Nakahara and Nagayama [3] studied underwater shock waves emanated from surface of an optical fiber by pulse Nd:YAG laser input using shadowgraph technique. Their qualitative study limited to visualization of shock waves at its early stage. The present research aims to clarify quantitatively process of the shock wave generation by direct laser beam irradiation through optical fibers, growth and behavior of generated cavities, and structure of heat induced flow in front of the optical fiber.


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