scholarly journals Numerical Investigation of the Collision Damage and Residual Strength of a Floating Bridge Girder

2018 ◽  
Author(s):  
Yanyan Sha ◽  
Jørgen Amdahl ◽  
Cato Dørum ◽  
Zhaolong Yu
Keyword(s):  
Residual Strength ◽  
Strength Index ◽  
Damage Level ◽  
Critical Design ◽  
Collision Response ◽  
Parametric Studies ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Floating Bridges ◽  
Fast Prediction

For bridges across wide and deep waterways, fixed foundation structures are not possible to be built due to technical restrictions. Alternatively, pontoon supported floating bridges which do not require fixed foundations can be installed. As the girders of floating bridges may have a low clearance from the sea level, a critical design consideration is the capability of the girder to resist the collision of passing ships. It is hence important to investigate the collision response of the bridge girder and evaluate girder residual strength after the collision. In this paper, finite element (FE) models of a ship deckhouse and a floating bridge girder are established. The girder response to ship deckhouse collision is investigated through integrated numerical simulations. Parametric studies are conducted to compare the girder response for various girder designs and collision scenarios. The residual strength of the girder after in damaged condition is also investigated. Based on the numerical results, a residual strength index (RSI) is proposed for fast prediction of the girder damage level based on the absorbed energy.

Hydrodynamical Aspects of Pontoon Optimization for a Side-Anchored Floating Bridge

2017 ◽  
Author(s):  
Arnt G. Fredriksen ◽  
Mads F. Heiervang ◽  
Per N. Larsen ◽  
Pål G. Sandnes ◽  
Bernt Sørby ◽  
...  
Keyword(s):  
Longitudinal Axis ◽  
Design Principles ◽  
Bottom Flange ◽  
Elastic Structures ◽  
Wave Regime ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Floating Bridges ◽  
Span Width

Long floating bridges supported by pontoons with span-widths between 100m and 200m are discrete hydro-elastic structures with many critical eigenmodes. The response of the bridge girder is dominated by vertical eigenmodes and coupled horizontal modes (lateral) and rotational modes (about the longitudinal axis of the bridge girder). In this paper it is focused on design principles to reduce the response with regards to these eigenmodes. It is shown for a floating bridge with 200m span-width that by inserting a bottom flange the vertical eigenmodes can be lifted out of wind driven wave regime. It is also shown that selecting a pontoon length that give cancellation of excitation forces is beneficial, and that the geometrical shaping of the pontoon can be efficient to decrease the bridge response.

Hydrodynamical Aspects of Pontoon Optimization for a Side-Anchored Floating Bridge

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Arnt G. Fredriksen ◽  
Mads F. Heiervang ◽  
Per N. Larsen ◽  
Pål G. Sandnes ◽  
Bernt Sørby ◽  
...  
Keyword(s):  
Longitudinal Axis ◽  
Design Principles ◽  
Bottom Flange ◽  
Elastic Structures ◽  
Wave Regime ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Floating Bridges ◽  
Span Width

Long floating bridges supported by pontoons with span-widths between 100 m and 200 m are discrete hydro-elastic structures with many critical eigenmodes. The response of the bridge girder is dominated by vertical eigenmodes and coupled horizontal modes (lateral) and rotational modes (about the longitudinal axis of the bridge girder). This paper explores the design principles used to reduce the response with regards to these eigenmodes. It is shown for a floating bridge with 200 m span-width that by inserting a bottom flange the vertical eigenmodes can be lifted out of wind-driven wave regime. It is also shown that selecting a pontoon length that leads to cancelation of horizontal excitation forces is beneficial, and that the geometrical shaping of the pontoon can be efficient to decrease the bridge response.

Design of floating bridge girders against accidental ship collision loads

2016 ◽  
Author(s):  
Yanyan Sha ◽  
Jørgen Amdahl
Keyword(s):  
Finite Element Models ◽  
Cruise Ship ◽  
Box Girder ◽  
Global Response ◽  
Ship Structure ◽  
Steel Box Girder ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Ship Collision ◽  
The Impact

The Norwegian Public Roads Administration is running a project “Ferry free coastal route E39” which includes replacing ferry crossings by bridges or tunnels across fjords in Western Norway. A floating bridge concept was proposed in the fjord-crossing project for Bjørnefjorden. As there are regular cruise routes passing by the bridge, it raises the concern for the consequences of accidental ship collision with the bridge girder. During the collision, the interactions between the bridge girder and the ship structure can be significant. Thus, in the design of the proposed bridge it is vital to evaluate the safety of the ship and the bridge. In this paper, detailed finite element models of a cruise ship and a steel box girder are developed. The impact scenarios and structural damages are studied. The results show that the proposed bridge girder design is generally safe to resist normal accidental ship collision loads. Numerical model of the whole bridge is also developed for further study of bridge global response subjected to ship collision load.

scholarly journals Deriving formulations for forecasting the ultimate strength of locally dented ring-stiffened cylinders under combined axial compression and radial pressure loads

2020 ◽  
Vol 23 (3) ◽  
pp. 640-654
Author(s):  
Do Quang Thang
Keyword(s):  
Ultimate Strength ◽  
Residual Strength ◽  
Good Accuracy ◽  
Uncertainty Modeling ◽  
Radial Pressure ◽  
Mean Value ◽  
Reduction Factor ◽  
The Novel ◽  
Test Results ◽  
Parametric Studies

Introduction: This paper focuses on the derived equations to evaluate the ultimate strength of ring-stiffened cylinders with local denting damage under combined loadings. The damage generation scenarios in this research are representing the collision accidents of offshore stiffened cylinders with supply ships. Methods: Numerical analysis of structures are performed using Abaqus software after validation against the experiments from the authors. The responses from seventeen cylinder specimens are analyzed to develop the numerical methods. Results: Good accuracy results were achieved when comparing the test results and the simulation results. Parametric studies are then performed on design examples of ring-stiffened cylinders when considering both intact and damaged conditions for assessing the reduction factor. Then, the novel simple design equations to assess the residual strength of ring-stiffened cylinders after ship collision are derived based on the regression analysis. These equations have good accuracy with mean value Xm (Uncertainty modeling factor) around 1.0 and together with COV (Coefficient of Variation) lower than 5.3%. Conclusion: The accuracy and reliability of the derived equations are validated by comparing it with the existing test data in open access. It is concluded that the proposed equations have high accuracy and reliability, and convenient application for the purpose of checking the residual strength of dented offshore cylinder under ship collisions.

scholarly journals Control system for installation and position keeping of interconnected flexible floating bridge

2020 ◽  
pp. 002029402096855
Author(s):  
Dong-Hun Lee ◽  
Young-Bok Kim
Keyword(s):  
Control System ◽  
Simulation Analysis ◽  
System Model ◽  
Heavy Vehicles ◽  
State Estimator ◽  
Adverse Conditions ◽  
Control Framework ◽  
Floating Bridge ◽  
Floating Bridges ◽  
Bridge System

We propose an approach for floating bridge installation and operation. A floating bridge aims to carry heavy vehicles, trucks, and people over a body of water. However, bridge installation and operation are mainly performed by humans regardless of adverse conditions, such as active combat or disaster occurrence. For installing and operating floating bridges under such conditions, we devised a solution based on control system design and automatic installation. The floating bridge system is controlled and positioned by a power propulsion system that is attached to floating units of the bridge. An optimal control system based on state estimator, which is designed using a robust control framework, is applied to install and operate the bridge. A simulation analysis and experiments demonstrate the effectiveness of proposed method on a bridge system model comprising five floating units.

scholarly journals Effects of Design Factors on Drag Forces and Deformations on Marine Aquaculture Cages: A Parametric Study Based on Numerical Simulations

2020 ◽  
Vol 8 (2) ◽  
pp. 125 ◽  
Author(s):  
Shuchuang Dong ◽  
Xinxing You ◽  
Fuxiang Hu
Keyword(s):  
Additive Model ◽  
Design Parameters ◽  
Marine Aquaculture ◽  
Drag Forces ◽  
Solidity Ratio ◽  
Parametric Studies ◽  
Net Cage ◽  
Fast Prediction ◽  
Bp Neural Network Model ◽  
Design Factors

In Japan, the marine aquaculture net cage has an important role in farming pacific bluefin tuna farming in oceans, and the design of the net cage needs to ensure robustness against hostile oceanic conditions. Accordingly, this study focuses on the drag forces and the cage volume of the net cage, and on their variations induced by different design parameters (netting solidity ratio, netting height, and bottom weight). A series of parametric studies on drag force and deformation of the net cage was conducted using a numerical simulation model. Accordingly, the contribution of each parameter to the drag and volume was analyzed using a generalized additive model. The results indicate that the bottom weight had the highest contribution to the holding ratio of the cage volume, whereas the netting height had the highest contribution to the drag coefficient of the net cage. Finally, a fast prediction model was created by a backpropagation (BP) neural network model and was examined for the accurate prediction of the objective variables.

Residual Strength Assessment of Ships after Collision Grounding

1998 ◽  
Vol 35 (01) ◽  
pp. 38-54
Author(s):  
Jeom Kee Paik ◽  
Anil K. Thayamballi ◽  
Soo Hong Yang
Keyword(s):  
Residual Strength ◽  
Bending Strength ◽  
Bending Moment ◽  
Accurate Method ◽  
Strength Index ◽  
Strength Assessment ◽  
Hull Girder ◽  
Section Modulus ◽  
Strength Based ◽  
Ultimate Bending Strength

The aim of this study is to develop a fast and reasonably accurate method for assessing collapse of the hull girder in the damaged condition. Location and amount of collision and grounding damage are prescribed. The possibility of hull collapse is explored by a comparison of the applied extreme bending moment and the ultimate hull strength which are estimated using design oriented methods and formulas• Two types of residual strength index, namely the section modulus based residual strength index and the ultimate bending strength based residual strength index, are defined. The method developed in this paper should be useful for preliminary structural design of a ship hull in accidental situations• It should also be potentially useful as one element of a decision making process related to salvage and rescue.

Collision Response of Bridge Girder with Shearkeys Subjected to Seismic Loads

2011 ◽  
Vol 90-93 ◽  
pp. 1539-1542
Author(s):  
Bo Wang ◽  
Yu Xiang Liu
Keyword(s):  
Seismic Loads ◽  
Analysis Program ◽  
Collision System ◽  
Element Analysis ◽  
Motion Feature ◽  
Rubber Bearing ◽  
Collision Response ◽  
The Finite Element Analysis ◽  
Calculation Results ◽  
Bridge Girder

In return for the collision response of bridge girder with shearkey subjected to seismic loads, a simplified dynamic model has been built by using the finite element analysis program Ansys/Ls-dyna. Based on the analysis of calculation results, the motion feature of this model is unfolded. Also, the stress response and characteristic at the bottom of shearkeys are analyzed, which are the most important parameters reflecting the cracking of shearkeys. Furthermore, the deformation of rubber bearing is elaborated to illustrate the collision of bridge girder with shearkeys. Finally, other key properties about the bridge girder of this collision system are addressed.

scholarly journals Comparative Study of the Floating Bridge Components

2021 ◽  
Vol 9 (VII) ◽  
pp. 258-262
Author(s):  
Prof. A. N. Humnabad
Keyword(s):  
Comparative Study ◽  
Limited Information ◽  
Different Types ◽  
Floating Bridge ◽  
Floating Bridges ◽  
Almost All ◽  
The Given

Floating bridge is a set of specialized shallow draft boats or floats hyperlink collectively to cross the river or canal or lake. With a track or deck most early floating bridge had been built for the features of the battle. There are numerous kinds of floating bridges relying on the conditions of the land and the type of barriers to cross. The principle behind floating bridge concept is the Archimedes’ principle of buoyancy. This study was made to review previous studies concerned about the floating bridges. Almost all the study concerned with floating bridge components and their suitability with the given condition. only limited information is available for floating bridges in many aspects. In this study we have covered the different types of pontoons, access to bridge, navigational openings, mooring systems, etc. are the most important parts of floating bridge.

Research on Multi-Level Fuzzy Evaluation for Safety of Floating Bridge in Complicated Engineering Environment

2013 ◽  
Vol 312 ◽  
pp. 928-933
Author(s):  
Yin Zhi Zhou ◽  
Jian Ping Wang
Keyword(s):  
Risk Factors ◽  
Evaluation Model ◽  
Safety Evaluation ◽  
Fuzzy Evaluation ◽  
Factors Affecting ◽  
Evaluation Indexes ◽  
Bridge Safety ◽  
Engineering Environment ◽  
Floating Bridge ◽  
Floating Bridges

In this paper, according to the characteristics such as great traffic throat role, obvious target and easy-to-expose, and poor protection ability of the floating bridges established in wartime and on the basis of comprehensively analyzing all risk factors affecting the floating bridges, a floating-bridge safety evaluation indexes system and a grey matter-element evaluation model 41 specific factors in the complex environment containing are established using enemy's threat, commanding decision, river environment, personnel's operation, equipment's quality, load passing and other risk factors encountered by the floating bridges as the primary indexes. Then, a safety evaluation is made in combination with a floating bridge setting-up case, thus drawing up a conclusion that the safety of this floating bridge is in a moderate state. Meanwhile, the main factors affecting the safety of the floating bridges are determined, thus providing certain references for the safety evaluation of other engineering.

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