Methods and tools for loads and load effects A study on the effect of heavy weather avoidance on the wave pressure distribution along the midship transverse section of a VLCC and a bulk carrier

The external wave pressure distributions along the transverse section in the midship region of a VLCC are evaluated in this paper. The commercial hydrodynamic code WASIM issued by DnV has been adopted to perform the hydrodynamic computation. The ship hulls have been discretized with coarser and finer mesh to investigate the effect of panel size on the hydrodynamic pressures. It is found that the difference between these two mesh finenesses is small. It is also found that the roll damping has a significant influence on the wave pressure of vessel especially in beam sea. A sensitivity analysis is carried out in the sense of assessing the influence of the roll damping on the wave pressure. Finally, the long term prediction of the wave pressure has been compared for different roll damping values.

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The Research Progress in a New Kind of Anti-Blast Wall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.744-746.1749 ◽

2015 ◽

Vol 744-746 ◽

pp. 1749-1752

Author(s):

Zhi Gang Zhang ◽

Ming Zhao Li ◽

Da Qing Kong ◽

Tao Ge ◽

Chun Ju Wang

Keyword(s):

International Trade ◽

Pressure Distribution ◽

Blast Wave ◽

Blast Load ◽

Research Progress ◽

Distribution Law ◽

Wave Pressure ◽

Rotation Model

Anti-blast wall can effectively reduce blast load and, therefore protect human and structures from external explosion. A new kind of anti-blast wall, HESCO Bastion wall (HB wall), was designed by the QIAOSHI(China) International Trade Limite. The research about the HB wall was mainly focus on the construction of rotation model and the anti-overturn stability of the wall, but no research could be found on the blast wave pressure distribution law behind the HB wall, the anti-penetration capability and the assembling mode of the HB wall. In this paper, research progress of the HB wall has been presented, research ideas about the HB wall have been put forward.

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STUDY OF STATISTICAL CHARACTERISTICS OF IRREGULAR WAVE PRESSURE ON A COMPOSITE BREAKWATER

Coastal Engineering Proceedings ◽

10.9753/icce.v20.131 ◽

1986 ◽

Vol 1 (20) ◽

pp. 131

Author(s):

Chien-Kee Chang ◽

Ching-Her Hwang

Keyword(s):

Pressure Distribution ◽

Wave Height ◽

Wave Force ◽

Shock Pressure ◽

Irregular Waves ◽

Statistical Characteristics ◽

Wave Forces ◽

Incoming Wave ◽

Wave Pressure ◽

Irregular Wave

Wave pressure is the most important external force for the design of breakwater. During recent years, there has been considerable development in the technology of vertical face breakwater; however, there is no reliable method to compute wave forces induced by irregular waves. The purpose of this study is to obtain statistical characteristics of irregular wave pressure distribution from the data of model tests. The results of this study shown that vertical face breakwater under the action of irregular waves, some waves are reflected, so that the next wave breaks a critical distance resulting in a rapidly rising shock pressure on the breakwater. On the average, the wave pressure increase with incoming wave height, but the maximum wave force does not necessarily occur for the largest wave height. It can be occurred for serval larger wave group in an appropiate phase composition. The irregular wave pressure distribution on the breakwater is quite uniform; the ratio of tested and calculated wave pressures decreases with the reduction of relative crest height of breakwater. Coda formula can predict the total horizontal force of the upper part of breakwater quite well except exetreme shock pressure occurred by non-breaking waves. Wave forces calculated by Miche-Rundgren and Nagai wave force formula are about 10% cummulated exceeding percentage of wave force obtained from model test.

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Estimation of Tsunami Force Acting on Rectangular Structures

Journal of Disaster Research ◽

10.20965/jdr.2009.p0404 ◽

2009 ◽

Vol 4 (6) ◽

pp. 404-409 ◽

Cited By ~ 45

Author(s):

Koji Fujima ◽

◽

Fauzie Achmad ◽

Yoshinori Shigihara ◽

Norimi Mizutani ◽

...

Keyword(s):

Pressure Distribution ◽

Standing Wave ◽

Tsunami Wave ◽

Wave Force ◽

Total Force ◽

Force Estimation ◽

Wave Pressure ◽

Estimation Equations ◽

Building Models

Hydraulic experiments were conducted to estimate tsunami wave force acting on rectangular onshore structures. Used building models placed at several distances from a shoreline. Wave pressure was measured at points on exposed structures. Impact and standing-wave pressure at different points peaked at different moments in time, so tsunami force tended to be overestimated by integrating maximum wave-pressure distribution envelope. Measured total force was thus used to formulate tsunami force estimation equations. Hydrostatic formula was successful for structures near a shoreline, despite large scattering for structures far from a shoreline. Hydrodynamic formula was successful in all cases, although inertia was considerable for structures near a shoreline.

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Evaluation of Tsunami Wave Loads Acting on Walls of Confined-Masonry-Brick and Concrete-Block Houses

Journal of Disaster Research ◽

10.20965/jdr.2014.p0976 ◽

2014 ◽

Vol 9 (6) ◽

pp. 976-983 ◽

Cited By ~ 2

Author(s):

Gaku Shoji ◽

◽

Hirofumi Shimizu ◽

Shunichi Koshimura ◽

Miguel Estrada ◽

...

Keyword(s):

Pressure Distribution ◽

Structural Damage ◽

Failure Modes ◽

Tsunami Wave ◽

Concrete Block ◽

Wave Loads ◽

Wave Load ◽

Confined Masonry ◽

Wave Pressure ◽

Horizontal Wave

Damage to confined-masonry-brick or concrete-block house was assessed for being subjected to a tsunami wave load. This study was prompted by recent three tsunamis – one during 2001 on the Near Coast of Peru, one in 2009 in the Samoa Islands, and one in 2010 in Maule, Chile. We analyzed 13 damaged walls from 10 single-storey houses located near the coastline. We focused on evaluating the tsunami wave pressure distribution on house walls. Based on the formula proposed by Asakura et al. (2000) to evaluate tsunami wave pressure distribution on a structural component located on land behind on-shore structures, which is used for designing a tsunami evacuation building, we identify the values of horizontal wave pressure indexain Asakura’s formula for walls and discuss the boundary value ofaat which a wall presents structural damage, such as in collapse and cracking failure modes.

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TYPICAL WAVE PRESSURE DISTRIBUTION OF SETBACK PARAPET BREAKWATER CAISSON WITH CYLINDICAL PILER

PROCEEDINGS OF CIVIL ENGINEERING IN THE OCEAN ◽

10.2208/prooe.16.13 ◽

2000 ◽

Vol 16 ◽

pp. 13-18

Author(s):

Teruo TOYOSHIMA ◽

Toshihiro SAKAKI ◽

Atsumi TAMIYA ◽

Takahiro KAWASAKI ◽

Toru MORIMOTO ◽

...

Keyword(s):

Pressure Distribution ◽

Wave Pressure

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Wave Response of Underwater Observation Tower Constructed at the Breaker Zone

Volume 2 ◽

10.1115/esda2004-58339 ◽

2004 ◽

Author(s):

Takahiro Sasaki ◽

Osamu Saijo ◽

Koichi Maruyoshi

Keyword(s):

Cylindrical Shell ◽

Pressure Distribution ◽

Wave Breaking ◽

Circular Cylindrical Shell ◽

Added Mass ◽

Simple Equation ◽

Breaking Force ◽

Underwater Observation ◽

Wave Pressure ◽

Sea Bed

There exist eight underwater observation towers in Japan. Seven of them have been built by vertical circular cylindrical shell structure, which are fixed at the sea bed like cantilever. And the other one is constructed of floating structure. Among the seven fixed-type structures, one stands under the frozen sea. The underwater observation towers are surrounded by sea water, and the inside is perfectly a close-spaced. Sightseers and several interested people visit to observe the undersea scene. Therefore, top priority must be given to structure safety. There is a vast existence of various creatures within the outstanding underwater scene which needed to be maintained to proliferate life. In order to satisfy with convenient access and outstanding scene, most structures have been built at the breaker zone. This paper presents the following contents: 1) Assuming that the underwater observation tower is constructed by vertical circular cylindrical shell, natural frequency analysis will be shown using present simple equation of added mass. We developed this equation uniquely based on fluid-structure interaction problem through water tank experiment and systematic numerical calculation. 2) Sawaragi, et al had presented wave breaking force acting on the vertical cylinder through the experiment. With reference to the force given by total force, we have newly extended its force to the wave pressure distribution so as to correspond to FEM analysis. We will show this developed method with regard to wave pressure distribution on the surface of cylindrical shell. 3) Using this simple equation of added mass and nodal forces obtained from wave breaking force, a procedure of calculation will be shown with demonstration. The evaluation and the validity in terms of added mass, load arrangement and responses will be discussed through the comparison of experimental result.

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