Probabilistic Risk Prediction of Submarine Pipelines Subjected to Underwater Explosion Shock

1999 ◽  
Vol 121 (4) ◽  
pp. 251-254 ◽  
Author(s):  
Z. Zong ◽  
K. Y. Lam ◽  
G. R. Liu
Keyword(s):  
Shock Loading ◽  
Simple Procedure ◽  
Underwater Explosion ◽  
Coupling Model ◽  
Oil Pipeline ◽  
Structure Interaction ◽  
The Monte Carlo Method ◽  
Underwater Shock ◽  
Interaction Problem ◽  
Failure Probabilities

A simple procedure is proposed in this paper to estimate the global failure probabilities of a submarine oil pipeline subjected to underwater explosion shock wave. The deterministic response of a pipeline subjected to an underwater shock loading is first given by solving a simplified fluid-structure interaction problem. Compared with an FEM/BEM coupling model, the present method gives good results at much lower computational efforts. Then, the Monte Carlo method is used to find the global failure probabilities of the pipeline. Finally, a practical example is given.

Probabilistic Failure of a Cracked Submarine Pipeline Subjected to the Underwater Shock

2000 ◽  
Vol 123 (3) ◽  
pp. 134-140
Author(s):  
K. Y. Lam ◽  
Z. Zong ◽  
Q. X. Wang
Keyword(s):  
Monte Carlo ◽  
Simple Procedure ◽  
Underwater Explosion ◽  
Crack Model ◽  
Tension Stress ◽  
Submarine Pipeline ◽  
Fracture Failure ◽  
The Monte Carlo Method ◽  
Underwater Shock ◽  
Good Agreement

The failure of a cracked submarine pipeline subjected to the underwater explosion shock is probabilistically analyzed in this paper. A simple procedure is presented, in which the Monte Carlo method is used to estimate the bending stress distribution, and an analytical method is used to estimate the fracture failure probability. The results obtained from the present method are compared with those obtained from direct Monte Carlo simulations. Both are in good agreement. From the studies in this paper, it is concluded that the most dangerous case is that the crack is perpendicular to the tension stress. The influence of crack model uncertainty is significant. FOSM method is also used, which greatly underestimates the failure probabilities for the problem studied in this paper.

Analytical Modeling of the Underwater Shock Response of Rigid and Elastic Plates Near a Solid Boundary

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
Qinyuan Li ◽  
Michail Manolidis ◽  
Yin L. Young
Keyword(s):  
Rise Time ◽  
Shock Loading ◽  
Fluid Structure Interaction ◽  
Damping Coefficient ◽  
Solid Boundary ◽  
Material Damping ◽  
Fluid Structure ◽  
Fixed Boundary ◽  
Structure Interaction ◽  
Underwater Shock

In this paper, analytical solutions are derived for the case when an elastic water-backed plate (WBP) is subject to an exponential shock loading near a fixed solid boundary. Two cases, a rigid plate and an elastic plate represented by two mass elements connected by a spring and a dashpot, are studied. The analytical solution is extended from Taylor's (1963, “The Pressure and Impulse of Submarine Explosion Waves on Plates,” Scientific Papers of Sir Geoffrey Ingram Taylor, Vol. 3, G. K. Batchelor, ed., Cambridge University Press, Cambridge, UK, pp. 287–303) floating air-backed plate (ABP) model and the water-backed plate model of Liu and Young (2008, “Transient Response of Submerged Plates Subject to Underwater Shock Loading: An Analytical Perspective,” J. Appl. Mech., 75(4), 044504; 2010, “Shock-Structure Interaction Considering Pressure Precursor,” Proceedings of the 28th Symposium on Naval Hydrodynamics, Pasadena, CA). The influences of five parameters are studied: (a) the distance of the fixed boundary from the back plate d, (b) the fluid structure interaction (FSI) parameter φ of the plate, (c) the stiffness of the plate as represented by the natural frequency of the system T, (d) the material damping coefficient CD of the plate, and (e) the pressure precursor (rise) time θr. The results show that the pressure responses at the front and back surfaces of the plate are greatly affected by the proximity to the fixed boundary, the fluid-structure interaction parameter, the ratio of the shock decay time to the natural period of the structure, and the rise time of incident pressure. The effect of structural damping (assuming a typical material damping coefficient of 5%) is found to be practically negligible compared to the other four parameters.

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.

Transient Response of Submerged Plates Subject to Underwater Shock Loading: An Analytical Perspective

2008 ◽  
Vol 75 (4) ◽  
Author(s):  
Zhanke Liu ◽  
Yin L. Young
Keyword(s):  
Structural Dynamics ◽  
Transient Response ◽  
Shock Loading ◽  
Structural Response ◽  
Small Range ◽  
Pressure Loading ◽  
Structure Interaction ◽  
Shock Response ◽  
Analytical Perspective ◽  
Underwater Shock

In this paper, Taylor’s floating air-backed plate (ABP) model is extended to the case of a submerged water-backed plate (WBP) within the acoustic range. The solution of the WBP is cast into the same format as that of the ABP with a modified fluid-structure interaction (FSI) parameter, which allows a unified analysis of the ABP and WBP using the same set of formulas. The influence of back conditions on fluid and structural dynamics, including fluid cavitation, is systematically investigated. Asymptotic limits are mathematically identified and physically interpolated. Results show that the WBP experiences lower equivalent pressure loading, reduced structural response, and hence lower peak momentum gaining. The time to reach peak momentum is shorter for the WBP than for the ABP. Cavitation is found to be almost inevitable for the ABP, while relevant to the WBP only for a small range of the FSI parameter. Implications to shock response of submerged structures are briefly discussed.

Dynamic Viscoplastic Response of a Circular Plate Subjected to Underwater Shock

2012 ◽  
Vol 56 (02) ◽  
pp. 71-79
Author(s):  
Z. Zong ◽  
Y. F. Zhang ◽  
L. Zhou
Keyword(s):  
Circular Plate ◽  
Underwater Explosion ◽  
Experimental Tests ◽  
Correct Prediction ◽  
Plastic Behavior ◽  
Marine Structures ◽  
Plastic Deformations ◽  
Structure Interaction ◽  
Double Phase ◽  
Underwater Shock

A structure subjected to underwater shock exhibits surprising dynamic behavior, different from the permanent plastic deformation of a structure subjected to air blast, due to the presence of complicated fluid-structure interaction (FSI) effect. Previous studies of a circular plate subjected to underwater shock indicate that there exist large discrepancies between theoretical and experimental results of plastic deformations. Herein we thus propose a new double-scale and double-phase (DSDP) FSI model for correct prediction of the dynamic plastic behavior of a circular plate subjected to underwater shock. Results obtained from this DSDP model are compared with several experimental tests, with excellent agreement observed. This model is believed useful for further implementation in those software programs that handle underwater explosion and its effects on marine structures.

The Influence of Flyer Momentum on an Aluminium Plate’s Response to Underwater Shock Loading

2018 ◽  
Vol 35 (02) ◽  
pp. 267-278
Author(s):  
X. He ◽  
J. L. Rong ◽  
D. L. Xiang ◽  
H. Y. Wei ◽  
C. H. Hu ◽  
...  
Keyword(s):  
Shock Waves ◽  
Shock Loading ◽  
Specific Impulse ◽  
Underwater Explosion ◽  
Theoretical Data ◽  
Experimental Results ◽  
Experimental Device ◽  
Simulation Accuracy ◽  
Underwater Shock

ABSTRACTAn underwater shock loading experimental device is used to simulate underwater explosion shock waves. The aim of this study is to investigate the influence of flyer momentum on the response of an aluminium plate to this underwater shock loading experimental device. The simulation accuracy can be verified by comparing theoretical data with the simulation and experimental results. Through simulations, an aluminium plate’s deformation and pressure specific impulse can be determined when flyers impact the piston at different velocities but at the same momentum. The aluminium plate's deformation and pressure specific impulse are constant when the flyers had constant momentum because both are directly proportional to the flyer momentum. The results have an important practical value for understanding and using this type of experimental device.

A COMPARATIVE DAMAGE STUDY OF AIR- AND WATER-BACKED PLATES SUBJECTED TO NON-CONTACT UNDERWATER EXPLOSION

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1311-1318 ◽  
Author(s):  
R. RAJENDRAN ◽  
J. M. LEE
Keyword(s):  
Damage Assessment ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Ship Design ◽  
Experimental Results ◽  
Underwater Shock ◽  
Motivating Factor ◽  
Damage Study ◽  
Side Shell

The response of the side shell to non-contact underwater explosion is of major concern in ship design. While extensive research is carried out on air-backed plates, relatively less attention is paid to water-backed plates. Nevertheless, the response of the water-backed plates becomes relevant when the water filled side shells are exposed to an underwater shock loading. Availability of scant information on the experimental results of water-backed plates is the primary motivating factor to make analytical estimates. These estimates are provided in comparison with an air-backed plate for identical attack geometry and target parameters. This work aims to bring out a comparative procedure for the damage assessment between air- and water-backed plates so that the response of the latter can be presented in terms of that of the former.

Promotion of Thawing Frozen Soil by Shock Wave Loading

2013 ◽  
Vol 767 ◽  
pp. 205-210
Author(s):  
Toshiaki Watanabe ◽  
Hideki Hamashima ◽  
Hironori Maehara ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Water Layer ◽  
Frozen Soil ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Underwater Shock Wave ◽  
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, Russia, Norway, and Sweden, etc. In order to check about that influence we tried to give an actual frozen soil a shock wave. We could get a result that existence of water layer serves an important role in promotion of thawing by the shock loading to the frozen soil. That role was confirmed from the result of numerical simulation.

A new effective method to predict the permanent deformation of plane plates subjected to underwater shock loading

2010 ◽  
Vol 225 (5) ◽  
pp. 1069-1075 ◽  
Author(s):  
L-J Li ◽  
W-K Jiang
Keyword(s):  
Shock Loading ◽  
Permanent Deformation ◽  
Underwater Explosion ◽  
Numerical Results ◽  
Gas Bubble ◽  
Computation Efficiency ◽  
Plane Plate ◽  
Underwater Shock ◽  
Structure Domain ◽  
Good Agreement

Theoretical analysis of the shock loading acting on a plane plate is performed for an underwater explosion. An effective new numerical method is used to simulate the plate plastic permanent deformation based on the shock loading acting on the plate. During the numerical simulation, only the structure domain is modelled and gas bubble reloading is ignored, and so computation efficiency is highly improved. The numerical results are modified based on the distribution of shock energy during the underwater explosion, and the modified numerical results are in good agreement with the experimental results.

Numerical Simulation for Development of Pressure Vessel for Food Processing by Shock Loading

2006 ◽  
Author(s):  
Masahiko Otsuka ◽  
Toshiaki Watanabe ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Numerical Analysis ◽  
Pressure Vessel ◽  
Food Processing ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Underwater Shock Wave ◽  
Reflected Wave ◽  
Underwater Shock

In this study, it has aimed at the design of the pressure vessel where an underwater shock wave is applied to food efficiently. This study aims at the desigh of a pressure vessel in which the underwater shock wave generated by the underwater explosion of detonating fuse was experimentally investigated by the optical observation and the pressure measurement. Therefore the pressure vessel is designed so that suitable pressure may apply on food. This designed vessel is evaluated by the numerical analysis that used LS-DYNA3D. The interaction of the underwater shock wave, the incident wave and the reflected wave are investigated by the numerical analysis. The agreement between the experimental results and the numerical analysis was found to be good.

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