Numerical Simulation for the Motion of the Flexible Floating Collision-Prevention System

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Xu-jun Chen ◽  
Guang-yuan Huang ◽  
Guang-huai Wu ◽  
Xue-feng Tang
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Calculation Method ◽  
Iterative Calculation ◽  
Collision Prevention ◽  
Prevention System ◽  
Movement Distance ◽  
History Of ◽  
The Relationship ◽  
Good Agreement

The flexible floating collision-prevention system (FFSCS) is a valuable floating engineering structure that can be used to prevent the uncontrolled ships to collide with the non-navigational bridge of a large sea-crossing bridge. The system is composed of buoys, block chains, mooring chains and gravity anchors. The deformation of the system under the acting of an uncontrolled ship as well as the movement distance of the gravity anchors are important factors that should be considered by the system designers. Based on the analysis of the relationship between the forces and the deformation of each part of the system, the approximately static equations are solved by a new numerical iterative calculation method. The position changes of the buoys, the movements of the anchors and the history of the inner forces of the block chains when a ship collides with the FFSCS are obtained by iterative calculation. The good agreement between the numerical value and the results of the model test indicate that the small balance method is a validation on the motion response simulation of the FFSCS under the acting of the uncontrolled ship. The results validate that FFSCS can stop the uncontrolled ship before it arrives at the place of the bridge.

Numerical Simulation of Ship Collision and Validations With Experimental Results

2021 ◽  
Author(s):  
Xiangbiao Wang ◽  
Chun Bao Li ◽  
Ling Zhu
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Structural Damage ◽  
Added Mass ◽  
Ship Motion ◽  
Time Dependent ◽  
Structural Deformation ◽  
Structure Interaction ◽  
Ship Collision ◽  
Good Agreement

Abstract Ship collision accidents occur from time to time in recent years, and this would cause serious consequences such as casualties, environmental pollution, loss of cargo on board, damage to the ship and its equipment, etc. Therefore, it is of great significance to study the response of ship motion and the mechanism of structural damage during the collision. In this paper, model experiments and numerical simulation are used to study the ship-ship collision. Firstly, the Coupled Eulerian-Lagrangian (CEL) was used to simulate the fluid-structure interaction for predicting structural deformation and ship motion during the normal ship-ship collision. Meanwhile, a series of model tests were carried out to validate the numerical results. The validation presented that the CEL simulation was in good agreement with the model test. However, the CEL simulation could not present the characteristics the time-dependent added mass.

scholarly journals Buried Depth of a Submarine Pipeline Based on Anchor Penetration

2019 ◽  
Vol 7 (8) ◽  
pp. 257
Author(s):  
Xueyuan Zhu ◽  
Qinglong Hao ◽  
Jie Zhang
Keyword(s):  
Numerical Simulation ◽  
Penetration Depth ◽  
Water Depth ◽  
Calculation Method ◽  
Water Surface ◽  
Submarine Pipeline ◽  
Projected Area ◽  
Actual Measurement ◽  
Calculation Results ◽  
The Relationship

Anchor penetration is an important issue involved in the study of submarine pipeline damage accidents. To explore the penetration of a ship’s anchor under certain conditions, this study investigated the motion and force of an anchor and formulated a calculation method for the bottoming speed of an anchor. Meanwhile, the depth of anchor penetration was calculated under different conditions according to bottoming speed through programming. Finally, the reliability of the calculation method for the penetration depth was verified by comparing the actual measurement and the numerical simulation. On the basis of the findings, the calculation results were further analyzed, and conclusions were derived regarding the relationship between anchor mass, the horizontal projected area of the anchor, the anchor height on the water surface, and water depth. The conclusions provide suggestions for the application of anchor penetration in terms of seabed depth with certain reference values.

Hydraulic Model and Numerical Simulation Study of Shuangwangcheng Pump Station

2011 ◽  
Vol 117-119 ◽  
pp. 647-651
Author(s):  
Chuan Qi Li ◽  
Wei Wang ◽  
Jie Gong ◽  
Xin Lai Zhao
Keyword(s):  
Numerical Simulation ◽  
Physical Model ◽  
Model Test ◽  
Hydraulic Model ◽  
Physical Model Test ◽  
Flow Conditions ◽  
Scheme Design ◽  
Model Studies ◽  
Pump Station ◽  
Good Agreement

Physical and numerical model studies were performed in order to study the flow conditions for the proposed pump station of Shuangwangcheng reservoir, Shouguang Ctiy. The flow velocity and the pressure distribution in the bidirectional culvert of Shuangwangcheng Pump Station had been obtained by hydraulic model test and numerical simulation. The physical model was constructed to a Froude scale of 1:20. A general conclusion was that, the computed results were good agreement with the data measured in physical model, and could be good complement for physical model test. Furthermore, negative pressure existing in discharge steep culvert in the initial scheme design was eliminated by moving the culvert controlling gate to the end of culvert in the modified scheme, and the flow conditions was improved.

Study on Numerical Simulation of Projectile Penetrating UHMWPE Fiber Layers and Effects of Projectile Parameters

2012 ◽  
Vol 630 ◽  
pp. 121-126
Author(s):  
Gong Wu Huang ◽  
Ai Jun Chen ◽  
Shao Min Luo ◽  
Cheng Xu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
High Speed ◽  
Research Approach ◽  
Finite Element Models ◽  
Uhmwpe Fiber ◽  
Penetration Ability ◽  
The Relationship ◽  
Better Than ◽  
Good Agreement

Finite element models of bullet penetrating UHMWPE fiber layers are established to study the relationship between parameters of projectile and penetration ability using LS-DYNA software. The numerical simulation results of penetration calculated in Lagrange algorithm are in good agreement with the real experimental results, which verify the validity of the finite element models and algorithm. The numerical results show that high speed and small angle of attack can improve the penetration ability, the penetration ability of oval projectile is better than flat head projectile. A valid and reliable research approach for evaluating the design of protective equipment and efficiency of projectiles are proposed.

scholarly journals Simulation of Wrinkling during Bending of Composite Reinforcement Laminates

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2374 ◽  
Author(s):  
Jin Huang ◽  
Philippe Boisse ◽  
Nahiène Hamila ◽  
Yingdan Zhu
Keyword(s):  
Numerical Simulation ◽  
Finite Elements ◽  
Boundary Conditions ◽  
Process Parameters ◽  
Numerical Approach ◽  
Optimal Process ◽  
Composite Manufacturing ◽  
Stress Resultant ◽  
History Of ◽  
Good Agreement

When a thick laminate is subjected to bending, under certain boundary conditions, wrinkles may appear and develop due to the inextensibility of the fibers. Wrinkling is one of the most critical defects in composite manufacturing. Numerical simulation of the onset and growth of such wrinkles is an important tool for defining optimal process parameters. Herein, several bending experiments of thick laminates are presented. They were found to lead to severe wrinkling and delamination of different kinds. It is shown that the history of loading changed the developed wrinkles. Stress resultant shell finite elements specific to textile reinforcement forming show their relevance to provide, for these wrinkles induced by bending, results in good agreement with the experiments, both with regard to the onset of the wrinkles and to their development. This numerical approach was used to improve the understanding of the phenomena involved in wrinkling and to define the conditions required to avoid it in a given process.

scholarly journals Research on uplift model test of single pile in sand

2021 ◽  
Vol 293 ◽  
pp. 01033
Author(s):  
Liuqing Huang ◽  
Huibiao Ma ◽  
Qiang Li ◽  
Ling Hu ◽  
Xinyi Li
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Strain Gauges ◽  
Single Pile ◽  
Model Pile ◽  
Distribution Laws ◽  
Pvc Pipe ◽  
Side Friction ◽  
Load Conditions ◽  
Good Agreement

This paper mainly uses the method of model test to study the ultimate uplift bearing characteristics of a single pile with different length-to-diameter ratios, mainly from the distribution laws of the uplift bearing capacity of the pile, the axial force of the pile and the side friction of the pile perform analysis. The model pile is made of PVC pipe, and resistance strain gauges are attached to both sides of the pipe. The strain value of the PVC pipe under different load conditions is measured to obtain the working behavior of the pile during the process of pulling out the pile. The result shows that the model test data is in good agreement with the numerical simulation.

An Engineering Method to Calculating JWL Constants of Explosives

2011 ◽  
Vol 94-96 ◽  
pp. 1737-1741
Author(s):  
Peng Fei Ning ◽  
De Gao Tang ◽  
Xia Qu
Keyword(s):  
Numerical Simulation ◽  
Equation Of State ◽  
Engineering Method ◽  
Iterative Calculation ◽  
Energy Behavior ◽  
Volume Energy ◽  
Good Agreement

The JWL equation of state is used worldwide to describe the pressure-volume-energy behavior of a detonating explosive. Obtaining the JWL constants needs experiments and iterative calculation, and so is expensive in time and economy. The JWL constants found in the literature is only suit for sample of a certain density, while it is simple to have slight density differences in application. In this paper an engineering method to calculating JWL constants while the density of explosive changed is proposed. An example is given out and it is shown good agreement between the experiment results and numerical simulation.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Investigating the Relationship Between Self-Esteem and Stigma Among Young Adults With History of Suicide Attempts

Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder
Keyword(s):  
Young Adults ◽  
Suicide Attempts ◽  
Self Esteem ◽  
High Risk Population ◽  
High Functioning ◽  
People With Mental Illness ◽  
History Of ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.

Misreading Egypt

2018 ◽  
Author(s):  
Jesse Schotter
Keyword(s):  
New Media ◽  
Narrative Form ◽  
Experimental Film ◽  
Tower Of Babel ◽  
Avant Garde ◽  
Sergei Eisenstein ◽  
History Of ◽  
The One ◽  
The Relationship ◽  
Modern Technologies

The first chapter of Hieroglyphic Modernisms exposes the complex history of Western misconceptions of Egyptian writing from antiquity to the present. Hieroglyphs bridge the gap between modern technologies and the ancient past, looking forward to the rise of new media and backward to the dispersal of languages in the mythical moment of the Tower of Babel. The contradictory ways in which hieroglyphs were interpreted in the West come to shape the differing ways that modernist writers and filmmakers understood the relationship between writing, film, and other new media. On the one hand, poets like Ezra Pound and film theorists like Vachel Lindsay and Sergei Eisenstein use the visual languages of China and of Egypt as a more primal or direct alternative to written words. But Freud, Proust, and the later Eisenstein conversely emphasize the phonetic qualities of Egyptian writing, its similarity to alphabetical scripts. The chapter concludes by arguing that even avant-garde invocations of hieroglyphics depend on narrative form through an examination of Hollis Frampton’s experimental film Zorns Lemma.

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