This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments ...This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.展开更多
This paper focused on the force characteristics of mooring lines of the common used gravity cage and sea station cage under floating status. In this experiment, total four cage models were designed which included two ...This paper focused on the force characteristics of mooring lines of the common used gravity cage and sea station cage under floating status. In this experiment, total four cage models were designed which included two gravity cage models, one sea station cage model and one quasi-sea station cage model. The gravity cages were made of the same materials but with different weighting system configurations. The sea station cage model and the quasi-sea station cage model were of the same diameter but the latter is 1.4 times in cage height to the former one which attributed greatly to the amplification of effective aquaculture volume up to 2.2 times. Four mooring lines were attached to each cage model on one side and the other side fixed on the bottom of the wave-current tank. Several kinds of experiment conditions were set, including pure current conditions, pure wave conditions and combined wave-current conditions. Forces were measured by four transducers attached to the bottom of the mooring lines respectively. Analysis was based on the resultant forces of the two current-ward or wave-ward mooring lines. Results from this study were presented and statically analyzed revealing that the quasi-sea station cage model suffered from greater forces compared with the other two kinds of cage models, which was more apparent under pure current conditions. It was interesting to find that the mass of the weighting system turned out to be relatively small effect on the forces acting on the gravity cage models under most conditions. Under pure wave conditions, several results of the forces acting on the gravity cage with heavier weighting system configuration were even smaller than those with lighter weighting system configuration. Conclusions were drawn that it was feasible to increase the mass of the weighting system properly to reduce the deformation of the netting system since it will not increase the forces acting on the gravity cages apparently. But it should be kept in mind that the operation of the cage will be affected dire展开更多
This study has focused on developing numerical procedures for the static and dynamic nonlinear analysis of mooring lines. A geometrically nonlinear finite element method using isoparametric cable element with two node...This study has focused on developing numerical procedures for the static and dynamic nonlinear analysis of mooring lines. A geometrically nonlinear finite element method using isoparametric cable element with two nodes is briefly presented on the basis of the total Lagrangian formulation. The static and dynamic equilibrium equations of mooring lines are established. An incremental-iterative method is used to determine the initial static equilibrium state of cable systems under the action of self weights, buoyancy and current. Also the Newmark method is used for dynamic nonlinear analysis of ocean cables. Numerical examples are presented to validate the present numerical method, and examine the effect of various parameters.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(No.2017R1A5A1014883).
文摘This paper presents dynamic-behavior comparisons and related forensic analyses of a submerged floating tunnel(SFT)between numerical simulation and physical experiment under regular and irregular waves.The experiments are conducted in the 3Dwave tank with 1:33.3 scale,and the corresponding coupled time-domain simulation tool is devised for comparison.The entire SFT systemconsists of a long concrete tunnel and 12 tubular aluminummooring lines.Two numerical simulation models,the Cummins equation with 3D potential theory including second-order wave-body interaction effects and the much simpler Morison-equation-based formula with the lumped-massbased line model,are designed and compared.Forensic analyses for mooring-line adjustments in the simulation are carried out in view of the best representation of the physical system.After that,the measured pre-tension distribution and systemstiffness of twelvemooring lines arewell reproduced in the numericalmodel.Subsequently,the dynamic responses and mooring tensions of the SFT are compared under regular and irregular waves.The measured and simulated results coincide reasonably well for both regular-and irregular-wave conditions.
文摘This paper focused on the force characteristics of mooring lines of the common used gravity cage and sea station cage under floating status. In this experiment, total four cage models were designed which included two gravity cage models, one sea station cage model and one quasi-sea station cage model. The gravity cages were made of the same materials but with different weighting system configurations. The sea station cage model and the quasi-sea station cage model were of the same diameter but the latter is 1.4 times in cage height to the former one which attributed greatly to the amplification of effective aquaculture volume up to 2.2 times. Four mooring lines were attached to each cage model on one side and the other side fixed on the bottom of the wave-current tank. Several kinds of experiment conditions were set, including pure current conditions, pure wave conditions and combined wave-current conditions. Forces were measured by four transducers attached to the bottom of the mooring lines respectively. Analysis was based on the resultant forces of the two current-ward or wave-ward mooring lines. Results from this study were presented and statically analyzed revealing that the quasi-sea station cage model suffered from greater forces compared with the other two kinds of cage models, which was more apparent under pure current conditions. It was interesting to find that the mass of the weighting system turned out to be relatively small effect on the forces acting on the gravity cage models under most conditions. Under pure wave conditions, several results of the forces acting on the gravity cage with heavier weighting system configuration were even smaller than those with lighter weighting system configuration. Conclusions were drawn that it was feasible to increase the mass of the weighting system properly to reduce the deformation of the netting system since it will not increase the forces acting on the gravity cages apparently. But it should be kept in mind that the operation of the cage will be affected dire
基金supported by the National Natural Science Foundation of China (Grant No.11072052)the National High Technology Research and Development Program of China (863 Program,Grant No.2006AA09A109-3)
文摘This study has focused on developing numerical procedures for the static and dynamic nonlinear analysis of mooring lines. A geometrically nonlinear finite element method using isoparametric cable element with two nodes is briefly presented on the basis of the total Lagrangian formulation. The static and dynamic equilibrium equations of mooring lines are established. An incremental-iterative method is used to determine the initial static equilibrium state of cable systems under the action of self weights, buoyancy and current. Also the Newmark method is used for dynamic nonlinear analysis of ocean cables. Numerical examples are presented to validate the present numerical method, and examine the effect of various parameters.
