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Journal

2012

Journal of Marine Science and Technology

Articles 1 - 13 of 13

Full-Text Articles in Mechanical Engineering

Effects Of Non-Newtonian Couple Stresses On The Dynamic Characteristics Of Wide Rayleigh Step Slider Bearings, Jaw-Ren Lin, Li-Ming Chu, Wei-Liang Liaw Oct 2012

Effects Of Non-Newtonian Couple Stresses On The Dynamic Characteristics Of Wide Rayleigh Step Slider Bearings, Jaw-Ren Lin, Li-Ming Chu, Wei-Liang Liaw

Journal of Marine Science and Technology

To provide more information in fluid-film lubricated bearings, the effects of non-Newtonian couple stresses on the dynamic characteristics of Rayleigh step slider bearings have been presented in this paper. According to the results, the effects of non-Newtonian couple stresses signify an improvement in the bearing characteristics. Comparing with the Newtonian-lubricant Rayleigh step bearing, the nonNewtonian couple stress effects provide an increase in the steady load-carrying capacity, the dynamic stiffness coefficient and the dynamic damping coefficient, as well as a reduction in the steady volume flow rate required. In order to guide the use of the present study, a numerical example …

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Rust-Expansion-Crack Service Life Prediction Of Existing Reinforced Concrete Bridge/Viaduct Using Time-Dependent Reliability Analysis, Ming-Te Liang, Jiang-Jhy Chang, Han-Tung Chang, Chi-Jang Yeh Aug 2012

Rust-Expansion-Crack Service Life Prediction Of Existing Reinforced Concrete Bridge/Viaduct Using Time-Dependent Reliability Analysis, Ming-Te Liang, Jiang-Jhy Chang, Han-Tung Chang, Chi-Jang Yeh

Journal of Marine Science and Technology

It is necessary to develop a calculation method to help in the making of feasible, reliable, and serviceable predictions for the service lives of bridge or viaduct structures. This article presents the basis for doing rust-expansion-crack service life predictions for existing reinforced concrete (RC) bridges and viaducts in chloride-laden environments based on timedependant reliability modeling due to the corrosion of steel in concrete. The corrosion process has three stages, the initiation (diffusion or carbonation) time (ti = tc), the depassivation time (tp), and the propagation (corrosion) time (tcorr). The rustexpansion-crack service lives (tcr) of existing RC bridges or viaducts can …

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Study On The Seismic Behavior Of Self-Anchored Suspension Bridges, Wen-Liang Qiu, Chang-Huan Kou, Chin-Sheng Kao, Shih-Wei Ma, Jiun Yang Aug 2012

Study On The Seismic Behavior Of Self-Anchored Suspension Bridges, Wen-Liang Qiu, Chang-Huan Kou, Chin-Sheng Kao, Shih-Wei Ma, Jiun Yang

Journal of Marine Science and Technology

The suspension bridge has a beautiful structural shape and an excellent spanning ability. The self-anchored suspension bridge has its main cables anchored directly on the two ends of the main girders, saving construction costs and time incurred during the anchorage construction of an earth-anchored suspension bridge. However, the feasibility of a self-anchored suspension bridge in a strong earthquake zone and the use of dampers to reduce seismic responses have yet to be fully investigated. Using the Yellow-River Road Bridge in Mainland as an example, this study sets out to analyze and investigate a series of seismic responses of a self-anchored …

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An Arc Code To Predict The Thermal Crack Of Welded Sample, Je-Ee Ho Aug 2012

An Arc Code To Predict The Thermal Crack Of Welded Sample, Je-Ee Ho

Journal of Marine Science and Technology

In this study, a numerical code with enthalpy method in upwind scheme is proposed to estimate the distribution of thermal stress in the molten pool, which is primarily determined by the type of the input power and travel speed of heating source. To predict the cracker deficit inside the workpiece, a simulated program satisfying the diagonal domination and Scarborough criterion provides a stable iteration. Meanwhile, an experimental performance, operated by robot arm “DR-400” to provide a steady and continuous arc welding, was also conducted to verify the simulated result. By surveying the consistence of molten pool bounded by contrast shade …

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Fuzzy Statistical Refinement For The Forecasting Of Tenders For Roadway Construction, Jeng-Wen Lin, Cheng-Wu Chen, Ting-Chang Hsu Aug 2012

Fuzzy Statistical Refinement For The Forecasting Of Tenders For Roadway Construction, Jeng-Wen Lin, Cheng-Wu Chen, Ting-Chang Hsu

Journal of Marine Science and Technology

Due to market competition, construction companies often place low bids when tenders are invited for domestic public construction projects. Over-competition can lead to vicious price wars to win a tender, which can in turn seriously affect the quality of construction. This study aims to establish an accurate Taiwan based model for the forecasting of the tendered price for roadway construction. This model is designed to assist the public sector to determine what would be a reasonable reserve price or award price. In order to ensure accurate predictions, a data classification system is established using fuzzy set theory. For each category …

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Studies Of The Effect Of Diffusion-Induced Chloride Binding On Chlorination Life Predictions For Existing Reinforced Concrete Bridges, Ming-Te Liang, Jiang-Jhy Chang, Tung-Wei Yu Aug 2012

Studies Of The Effect Of Diffusion-Induced Chloride Binding On Chlorination Life Predictions For Existing Reinforced Concrete Bridges, Ming-Te Liang, Jiang-Jhy Chang, Tung-Wei Yu

Journal of Marine Science and Technology

The chloride ions diffusion is one of important factors of corrosion of reinforced concrete (RC) structures. The total chloride concentration penetrated into concrete can be expressed as the sum of bound and free chloride concentrations. The principal purpose of this paper is to study the chlorination life prediction of existing RC bridges due to chloride binding effect. The investigation method is that the no binding, linear binding, Langmuir and Freundlich adsorption isotherms are substituted into the analytical solutions of linear (diffusivity D = constant) and non-linear (D ≠ constant) diffusion equations associated with initial and boundary conditions, respectively. The chlorination …

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A Manifold-Based Exponentially Convergent Algorithm For Solving Non-Linear Partial Differential Equations, Chein-Shan Liu Aug 2012

A Manifold-Based Exponentially Convergent Algorithm For Solving Non-Linear Partial Differential Equations, Chein-Shan Liu

Journal of Marine Science and Technology

For solving a non-linear system of algebraic equations of the type: Fi(xj) = 0, i, j = 1, …, n, a Newton-like algorithm is still the most popular one; however, it had some drawbacks as being locally convergent, sensitive to initial guess, and time consumption in finding the inversion of the Jacobian matrix ∂Fi /∂xj. Based-on a manifold defined in the space of (xi, t) we can derive a system of non-linear Ordinary Differential Equations (ODEs) in terms of the fictitious time-like variable t, and the residual error is exponentially decreased to zero along the path of x(t) by solving …

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Design Of Planning Level Ship Product Model For Ship Initial Design, Sungchul Shin, Soon-Sup Lee, Jong-Kap Lee, Kyung-Ho Lee Aug 2012

Design Of Planning Level Ship Product Model For Ship Initial Design, Sungchul Shin, Soon-Sup Lee, Jong-Kap Lee, Kyung-Ho Lee

Journal of Marine Science and Technology

This paper introduces a design of planning level ship product model (called SPPM hereinafter) based on ISO 10303 Standard for The Exchange of Product Model data (STEP). For the design of this model, the information modeling methodologies such as Integration Definition (IDEF) methods and Unified Modeling Language (UML) were reviewed, and a hybrid method was established. By using this method, ship initial design process was analyzed, and STEP-based information model and class libraries for SPPM were defined. For the data structure of this model, the shipbuilding Application Protocols (AP215, AP216 and Ship Common Model) of STEP were investigated and utilized …

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Slamming Induced Dynamic Response Of A Floating Structure, Mohammad Ali Lotfollahi-Yaghin1, Mehdi Rastgar, Hamid Ahmadi Apr 2012

Slamming Induced Dynamic Response Of A Floating Structure, Mohammad Ali Lotfollahi-Yaghin1, Mehdi Rastgar, Hamid Ahmadi

Journal of Marine Science and Technology

Study of the slamming phenomenon is one of the most important branches of the floating structure dynamics. Experimental study of the floating structure dynamics can be very expensive because it requires a long wave flume and a moving model. Hence, numerical methods are considered to be very useful and efficient tools for modeling and dynamic analysis of floating structures. In the present paper, slamming induced impulsive loads are investigated firstly. Afterwards, dynamic response of a barge under the slamming excitation is studied, and the natural frequencies and mode shapes are determined, using the FE software package, ANSYS. Critical cross sections …

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Constructing The Comprehensive Subsurface Structure Of Lanyang Plain, Chih-Hao Hsu, Sao-Jeng Chao, Shuh-Gi Chern, Howard Hwang Apr 2012

Constructing The Comprehensive Subsurface Structure Of Lanyang Plain, Chih-Hao Hsu, Sao-Jeng Chao, Shuh-Gi Chern, Howard Hwang

Journal of Marine Science and Technology

This study presents an integral approach to construct a comprehensive subsurface structure of Lanyang Plain. It is well known that geophysicists and engineers use different techniques to investigate the subsurface structure, and each of these techniques has its own advantages. Therefore, in this study, the excellent results from these two fields are selected and combined to provide a comprehensive profile of the subsurface structure of Lanyang Plain. In this study, the subsurface information on nine recording stations and digital boundary lines of Lanyang Plain based on the digital geologic map published by the Central Geological Survey are utilized to create …

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Semi-Analytical Solution For Radiation Of A Hollow Sphere With An Opening Hole In Finite Depth, Man-Sheng Dong, Guo-Ping Miao, Ju Fan, Ren-Chuan Zhu Feb 2012

Semi-Analytical Solution For Radiation Of A Hollow Sphere With An Opening Hole In Finite Depth, Man-Sheng Dong, Guo-Ping Miao, Ju Fan, Ren-Chuan Zhu

Journal of Marine Science and Technology

An investigation is conducted on radiation of a submerged hollow sphere with an opening hole in finite water depth in this article. Based on the linear theory, the method of multipole expansions is used to obtain the fluid velocity potential in the form of double series of the associated Legendre functions with the unknown coefficients of an infinite set. In terms of the body surface boundary condition and the matching condition between the inner and outer flows at the hole, the complex matrix equations for the coefficients of the series are established. The infinite sets of matrix equations are solved …

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Numerical Study On Significance Of Wind Action On 2-D Freak Waves With Different Parameters, Shiqiang Yan, Qingwei Ma Feb 2012

Numerical Study On Significance Of Wind Action On 2-D Freak Waves With Different Parameters, Shiqiang Yan, Qingwei Ma

Journal of Marine Science and Technology

This paper presents a numerical study on how the significance of wind action differs when varying the wave parameters. The quasi arbitrary Lagrangian-Eulerian finite element method (QALE-FEM) is used for this purpose. An improved model for wind-excited pressure and wind-driven current, which is recently developed by the authors of this paper [27], is coupled with the QALE-FEM. Many cases involving freak waves with different focusing time/point and frequency ranges under the action of winds are investigated. The results show that the significance of wind actions on freak waves strongly depends on the focusing time, the focusing point and the frequency …

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Transient Response Of Sloshing Fluid In A Three Dimensional Tank, Chih-Hua Wu, Bang-Fuh Chen Feb 2012

Transient Response Of Sloshing Fluid In A Three Dimensional Tank, Chih-Hua Wu, Bang-Fuh Chen

Journal of Marine Science and Technology

Sloshing waves in moving tanks have been studied numerically, theoretically and experimentally in the past several decades. Most reported studies have been for tanks excited by forcing motion in a limited number of directions and with fixed excitation frequencies throughout the forcing. In the present study, a time-independent finite difference method is used to simulate fluid sloshing in the three-dimensional tanks with arbitrary depths and the tanks are subject to a range of excitation frequencies with motions that exhibit multiple degrees of freedom. The developed numerical scheme is verified by rigorous benchmark tests, and the advantage and efficiency of the …

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