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Journal of Wuhan university of technology(Materials Science) 2005年第3期20卷 104-109页

作者：曹伟 state key laboratory of coastal and offshore engineering Dalian University of Technology

An experimental study on performance of plain concrete under triaxial constant-amplitude and variable amplitude tension- compression cyclic loadings was carded out. The low level of the cyclic stress is 0. 2f and the upper level ranges between 0. 20f and 0. 55f., while the constant lateral pressure is 0. 3 f . The specimen failure mode, the three-stage evolution rule of the longitudinal strains and the damage evolution law under cyclic loading were analyzed. Furthermore, Miner＇s rule is proved not to be applicable to the cyclic loading conditions, hereby, a nonlinear cumulative damage model was established. Based on the model the remaining fatigue life was evaluated. The comparison whh the experiment resuhs shaws that the model is of better precision and applicability.

关键词： concrete triaxial tension-compression Cyclic loading three-stage evolution rule nonlinear cumulative damage model

A composite numerical model for wave diffraction in a harbor with varying water depth

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Acta Oceanologica Sinica 2004年第2期23卷 367-375页

作者： ZHAOMing TENGBin statekeylaboratoryofcoastalandoffshoreengineering DalianUniversityofTechnologyDalian116024China

A composite numerical model is presented for computing the wave field in a harbor. The mild slope equation is discretized by a finite element method in the domain concerned. Out of the computational domain, the water depth is assumed to be constant. The boundary element method is applied to the outer boundary for dealing with the infinite boundary condition. Because the model satisfies strictly the infinite boundary condition, more accurate results can be obtained. The model is firstly applied to compute the wave diffraction in a narrow rectangular bay and the wave diffraction from a porous cylinder. The numerical results are compared with the analytical solution, experimental data and other numerical results. Good agreements are obtained. Then the model is applied to computing the wave diffraction in a square harbor with varying water depth. The effects of the water depth in the harbor and the incoming wave direction on the wave height distribution are discussed.

关键词： harbor wave diffraction finite element method boundary element method mild slope equation

A CONSERVATIVE UNSTRUCTURED STAGGERED GRID SCHEME FOR INCOMPRESSIBLE NAVIER-STOKES EQUATIONS

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Journal of Hydrodynamics 2010年第2期22卷 173-184页

作者： LV Biao JIN Sheng AI Cong-fang state key laboratory of coastal and offshore engineering Dalian University of Technology Dalian 116024China key laboratory of engineering Sediment of Ministry of Communications Tianjin Research Institute for WaterTransport Engineering Tianjin 300456 China

A finite-volume formulation is proposed to solve the three-dimensional,non-hydrostatic Navier-Stokes equations on an unstructured,staggered,z-lever grid,with the goal of simulating non-hydrostatic processes in the free-surface *** advection and diffusion terms in the momentum equation are discretized explicitly with the Eulerian scheme,which has the attractive property of being *** integral method of the top-layer pressure is applied to account for the full effects of non-hydrostatic pressure at the free-surface *** is shown that the results obtained with a small number of vertical layers（e.g.,2-3 layers） are in good agreements with experimental data or analytical solutions,demonstrating the efficiency and accuracy of the model in simulating a range of free-surface flow problems including wave motion and tide-induced motion.

关键词： unstructured staggered grid finite-volume formulation non-hydrostatic free surface flows

Charactersitics of Stress-strain Curve of High Strength Steel Fiber Reinforced Concrete under Uniaxial Tension

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Journal of Wuhan university of technology(Materials Science) 2006年第3期21卷 132-137页

作者：杨萌 state key laboratory of coastal and offshore engineering Department of Civil Engineering Dalian University of Technology Dalian 116023China

A whole of 110 specimens divided into 22 groups were tested with varying the volume fraction of steel fibers and the matrix strength of these specimens. The stress-strain behaviors of four types of steel fiber reinforced concrete （SFRC） under uniaxial tension were studied experimentally. When the matrix strength and the fiber content increase, the tensile stress and tensile strain vary differently according to the fiber type. The mechanisms of reinforcing effect for different types of fiber were analyzed and the stress-strain curves of the specimens were plotted. Some experimental factors for stress or strain of SFRC were given. A tensile toughness modulus Re0.5 was introduced to evaluate the toughness characters of SFRC under uniaxial tension. Moreover, the formula of the tensile stress-strain curve of SFRC was regressed. The theoretical curve and the experimental ones fit well, which can be used for references in construction.

关键词： steel fiber reinforced concrete high strength uniaxial tension soften characteristics stress-strain curve

Uniaxial Compressive Properties of Ultra High Toughness Cementitious Composite

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Journal of Wuhan university of technology(Materials Science) 2011年第4期26卷 762-769页

作者：蔡向荣徐世烺 state key laboratory of coastal and offshore engineering Dalian University of Technology

Uniaxial compression tests were conducted to characterize the main compressive performance of ultra high toughness cementitious composite （UHTCC） in terms of strength and toughness and to obtain its stress-strain relationships. The compressive strength investigated ranges from 30 MPa to 60 MPa. Complete stress-strain curves were directly obtained, and the strength indexes, including uniaxial compressive strength, compressive strain at peak stress, elastic modulus and Poisson＇s ratio, were calculated. The comparisons between UHTCC and matrix were also carried out to understand the fiber effect on the compressive strength indexes. Three dimensionless toughness indexes were calculated, which either represent its relative improvement in energy absorption capacity because of fiber addition or provide an indication of its behavior relative to a rigid-plastic material. Moreover, two new toughness indexes, which were named as post-crack deformation energy and equivalent compressive strength, were proposed and calculated with the aim at linking up the compressive toughness of UHTCC with the existing design concept of concrete. The failure mode was also given. The study production provides material characteristics for the practical engineering application of UHTCC.

关键词： ultra high toughness cementitious composite compressive strength compressive toughness fiber reinforcement

DEVELOPMENT AND APPLICATION OF A EUTROPHICATION WATER QUALITY MODEL FOR RIVER NETWORKS

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Journal of Hydrodynamics 2008年第6期20卷 719-726页

作者： ZHANG Ming-liang SHEN Yong-ming GUO Yakun state key laboratory of coastal and offshore engineering Dalian University of Technology Dalian 116023 China Department of Civil and Structural engineering The Hong Kong Polytechnic University Hong Kong China Department of engineering University of Aberdeen Aberdeen AB24 3UE UK

The Preissmann implicit scheme was used to discretize the one-dimensional Saint-Venant equations, the river-junction-fiver method was applied to resolve the hydrodynamic and water quality model for river networks, and the key issues on the model were expatiated particularly in this article. This water quality module was designed to compute time dependent concentrations of a series of constituents, which are primarily governed by the processes of advection, dispersion and chemical reactions. Based on the theory of Water Quality Analysis Simulation Program （WASP） water quality model, emphasis was given to the simulation of the biogeochemical transformations that determine the fate of nutrients, in particular, the simulation of the aquatic cycles of nitrogen and phosphorus compounds. This model also includes procedures for the determination of growth and death of phytoplankton. This hydrodynamic and water quality model was applied to calculate two river networks. As illustrated by the numerical examples, the calculated water level and discharge agree with the measured data and the simulated trends and magnitudes of water quality constituents are generally in good agreement with field observations. It is concluded that the presented model is useful in the pollutant control and in the determination of pollutant-related problems for river networks.

关键词： Preissmann implicit scheme river networks hydrodynamic model water quality model biogeochemical transformations three-step method

NUMERICAL SIMULATION OF EXTREME WAVE GENERATION USING VOF METHOD

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Journal of Hydrodynamics 2010年第4期22卷 466-477页

作者： ZHAO Xi-zeng RIAM HU Chang-hong SUN Zhao-chen Kyushu university Fukuoka Japan State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China RIAM Kyushu University Fukuoka Japan state key laboratory of coastal and offshore engineering Dalian University of Technology Dalian 116024 China

Numerical simulations of extreme wave generation are carried out by using the Volume Of Fluid（VOF） *** waves are generated based on wave focusing in a 2-D numerical *** validate the capability of the VOF-based model described in this article,the propagation of regular waves is computed and compared with the theoretical *** adjusting the phases of wave components,extreme waves are formed at given time and given position in the *** numerical results are compared with theoretical solutions and experimental *** is concluded that the present model based on the VOF technique can provide acceptably accurate numerical results to serve practical purposes.

关键词： extreme wave Volume Of Fluid (VOF) wave focusing wave tank regular wave

A STUDY ON UNSTEADY SEEPAGE FLOW THROUGH DAM

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Journal of Hydrodynamics 2009年第4期21卷 499-504页

作者： FU Jun-feng JIN Sheng state key laboratory of coastal and offshore engineering Dalian University of Technology Dalian 116024 China

A numerical model is proposed to simulate the unsteady seepage flow through dam, with both saturation and water head as variables to describe the seepage domain. Experiments of seepage flow through dam with unsteady conditions were conducted in laboratory to verify the reliability and the accuracy of the numerical model. The performance of the model is also assessed by comparing with analytical solutions. The examples show that the accuracy and the reliability of the model are adequate to handle seepage flow problems with complex conditions. It is also demonstrated that the method of determining the seepage surface through the saturation description is natural, logical and practical in actual applications. The method provides a relatively simple computing scheme, as compared with traditional methods.

关键词： saturation unsteady seepage saturated and unsaturated seepage finite element method

A CONSERVATIVE COUPLED FLOW/TRANSPORT MODEL WITH ZERO MASS ERROR

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Journal of Hydrodynamics 2009年第2期21卷 166-175页

作者： BAI Lu-hai JIN Sheng state key laboratory of coastal and offshore engineering Dalian University of Technology Dalian 116024China

A fully conservative form applied to a coupled system of two-dimensional water flow and solute motion is presented. A cell-centred finite volume method based on Roe＇s approximate Riemann solver with unstructured grids is formulated. The bed slope source terms are discretized following an upwind approach and a semi-implicit treatment is used for the friction source terms. The centered discretization of the diffusion terms is in an implicit way. It is shown that this numerical technique reproduces almost exactly the steady state of still water and enables to achieve zero numerical errors in unsteady flow over configurations with strong variations on bed slope. The model ensures a global conservation and positive values of both water level and solute concentration. Numerical results show the effectiveness of the model in solute transport over real complex geometries.

关键词： transport model shallow water flow coupled model wetting/drying conditions conservation complex topography

COMPUTATION OF FREE SURFACE FLOWS WITH HIGH RESOLUTION FINITE ELEMENT SCHEME

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Journal of Hydrodynamics 2003年第3期15卷 22-27页

作者： Jin Sheng, Zhang Ri-xiang, Pu Gao-jun Department of Civil engineering, state key laboratory of offshore engineering, dalian university of technology, dalian 1.602., china, DepartmentofCivilengineering StateKeyLaboratoryofOffshoreEngineeringDalianUniversityofTechnologyDalian116024China

A high-resolution finite element scheme is developed for the computation offree surface problems. The present higher-order accuracy scheme is obtained through the introductionof the difference of almost equal amount of diffusion and antidiffusion, where the antidiffusion isformulated as approximation to diffusion making use of consecutive gradient. The non-oscillatoryproperties are secured by limiters to preserve positivity constraints. The implement of the schemeis based on semi-discrete form and can be considered as reconstruction of the coefficient matrix ofalgebraic system, so, it can he conveniently used by either structured or unstructured meshes. Thepower and flexibility of the present high resolution VOF-FEM approach is validated by examplesincluding convective transport, dam breaking flow, and stilling basin flow in hydraulic engineering.

关键词： free surface flow high resolution finite element scheme