In slab column-shear wall structures,both the whole structure′s seismic behavior and failure mode are greatly influenced by the distribution of horizontal seismic forces between slab-column and shear wall.In this pap...In slab column-shear wall structures,both the whole structure′s seismic behavior and failure mode are greatly influenced by the distribution of horizontal seismic forces between slab-column and shear wall.In this paper,a pushover analysis of topical slab column-shear wall structure was carried out,the seismic shear force that the slab-column and shear wall should undertake was worked out,the influences of plastic internal force redistribution and structure stiffness characteristic value on horizontal seismic distribution were studied and the calculation formula was given.The analysis results showed that with the yield of the shear walls,the story shear force was undertaken by slab-columns correspondingly increased while with the decrease of characteristic value of stiffness of a structure,and the horizontal seismic force was undertaken by slab-columns correspondingly decreased.According to the code,the design of horizontal force distribution may be cause insecurity problems,so it is necessary to give the distribution law of horizontal seismic forces in slab-column shear wall structures as the supplement to the corresponding regulation of the Code.展开更多
A series of experimental studies about the force of internal solitary wave and internal periodic wave on vertical cylinders have been carried out in a two-dimensional layered internal wave flume. The internal solitary...A series of experimental studies about the force of internal solitary wave and internal periodic wave on vertical cylinders have been carried out in a two-dimensional layered internal wave flume. The internal solitary waves are produced by means of gravitational collapse at the layer thickness ratio of 0.2, and the internal periodic waves are produced with rocker-flap wave maker at the layer thickness ratio of 0.93. The wave parameters are obtained through dyeing photography. The vertical cylinders of the same size are arranged in different depths. The horizontal force on each cylinder is measured and the vertical distribution rules are researched. The internal wave heights are changed to study the impact of wave heights on the force. The results show that the horizontal force of concave type internal solitary wave on vertical cylinder in the upper-layer fluid has the same direction as the wave propagating, while it has an opposite direction in the lower-layer. The horizontal force is not evenly distributed in the lower fluid. And the force at different depths increases along with wave height. Internal solitary wave can produce an impact load on the entire pile. The horizontal force of internal periodic waves on the vertical cylinders is periodically changed at the frequency of waves. The direction of the force is opposite in the upper and lower layers, and the value is close. In the upper layer except the depth close to the interface, the force is evenly distributed; but it tends to decrease with the deeper depth in the lower layer. A periodic shear load can be produced on the entire pile by internal periodic waves, and it may cause fatigue damage to structures.展开更多
Due to increasing pressure on brand owners and distributors to avoid single use plastics such as plastic bundle packaging, a new bundle packaging that consists of corrugated board only, has been designed. Obviously th...Due to increasing pressure on brand owners and distributors to avoid single use plastics such as plastic bundle packaging, a new bundle packaging that consists of corrugated board only, has been designed. Obviously this new packaging should equally enable transportability. This study compares the transportability of bundles using corrugated board on the one hand and bundles using plastic collation shrink film on the other. In particular, the resistance to varying horizontal inertial forces is compared experimentally. All tested bundle packagings of corrugated board perform well above expectations and significantly better than shrink film packaging. All additional requirements regarding marketing, durability, consumer convenience, …are met.展开更多
A dual-baffled rectangular tank with different configurations is proposed to reduce the sloshing effect,and design optimization is conducted through numerical simulations with open-source software,namely OpenFOAM,base...A dual-baffled rectangular tank with different configurations is proposed to reduce the sloshing effect,and design optimization is conducted through numerical simulations with open-source software,namely OpenFOAM,based on the computational fluid dynamic model.A series of physical experiments in the dual-baffled rectangular tank is performed for model validation and design optimization with the measured water surface elevation distributions along the tank.The optimization uses the calculated maximum horizontal force exerted on the tank and entropy generation(EG)as the criterion.Results show that the dual-baffle configuration positioned at the tank center is more effective in reducing the sloshing than that of the single baffle when the relative baffle height and initial water depth ratio(Hb/Hw,where Hb and Hw represent baffle height and static water depth,respectively)are larger than 0.5.However,such an effect then diminishes when the ratio is larger than 0.75.The effect of the dual-baffle configuration on the sway motion under the condition of different motion amplitudes and frequencies is also evaluated.The results show that the reduction in the maximum horizontal force is almost the same for dual-and single-baffled configurations and reaches the minimum when the sway motion amplitude is near 0.03 m.The dual-baffled configuration for the angular frequency of the sway motion is more effective than the single-baffled in reducing the sloshing at the low angular frequencies but is only less effective at high angular frequencies.Furthermore,the optimal baffle inclination angle is 85°when the inclined straight and curved baffles are used,and curved baffles can successfully decrease the horizontal force exerted on the tank and EG.展开更多
Using linear water wave theory,three-dimensional problems concerning the interaction of waves with spherical structures in a fluid which contains a three-layer fluid consisting of a layer of finite depth bounded above...Using linear water wave theory,three-dimensional problems concerning the interaction of waves with spherical structures in a fluid which contains a three-layer fluid consisting of a layer of finite depth bounded above by freshwater of finite depth with free surface and below by an infinite layer of water of greater density are considered.In such a situation timeharmonic waves with a given frequency can propagate with three wavenumbers.The sphere is submerged in either of the three layers.Each problem is reduced to an infinite system of linear equations by employing the method of multipoles and the system of equations is solved numerically by standard technique.The hydrodynamic forces(vertical and horizontal forces)are obtained and depicted graphically against the wavenumber.When the density ratio of the upper and middle layer is made to approximately one,curves for vertical and horizontal forces almost coincide with the corresponding curves for the case of a two-layer fluid with a free surface.This means that in the limit,the density ratio of the upper and middle layer goes to approximately one,the solution agrees with the solution for the case of a two-layer fluid with a free surface.展开更多
The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs ha...The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs have been so far restricted to the water level above the bottom of the superstructure,which mainly occurs under the high tides or storm tides.However,based on recent engineering applications and experimental observations,the most severe conditions for CTBs are more likely to occur under a medium water level,because impulsive wave pressure may occur due to interactions between waves and the special chamber in CTBs.Meanwhile,during the most of construction and operation periods,the CTBs are mainly working under the medium water levels,i.e.,water levels below the bottom of the superstructure.In this study,the effects of main influence parameters on the horizontal wave force coefficient and wave transmission coefficient for open CTBs(with partially immersed side plates)under medium water levels were investigated based on a 3D numerical wave flume and corresponding empirical formulae were proposed.It is indicated that the location of the side plate related to the main caisson has significant influence on the hydrodynamic performance of CTBs.In engineering applications,the location of the side plate can be designed at b/L≤0.15 or b/L≥0.3(where b is the distance between the side plate and the front face of the main caisson and L is the incident wave length)for efficiently lowering the horizontal wave force and wave transmission.The flow mechanism of impulsive wave force on CTBs was revealed based on synchronous analyses of flow fields and pressure distribution.Through appropriate design of the height of the superstructure according to H/hD≤1.0 or H/hD≥1.5(where H is the incident wave height and hD is the distance between the still water level and the bottom of the superstructure),the likely impulsive wave pressure on the side plate can also be diminished.展开更多
文摘In slab column-shear wall structures,both the whole structure′s seismic behavior and failure mode are greatly influenced by the distribution of horizontal seismic forces between slab-column and shear wall.In this paper,a pushover analysis of topical slab column-shear wall structure was carried out,the seismic shear force that the slab-column and shear wall should undertake was worked out,the influences of plastic internal force redistribution and structure stiffness characteristic value on horizontal seismic distribution were studied and the calculation formula was given.The analysis results showed that with the yield of the shear walls,the story shear force was undertaken by slab-columns correspondingly increased while with the decrease of characteristic value of stiffness of a structure,and the horizontal seismic force was undertaken by slab-columns correspondingly decreased.According to the code,the design of horizontal force distribution may be cause insecurity problems,so it is necessary to give the distribution law of horizontal seismic forces in slab-column shear wall structures as the supplement to the corresponding regulation of the Code.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51279187 and 41174157)the Fundamental Research Funds for the Central Universities(Grant No.201262005)the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(Grant No.BS2013HZ014)
文摘A series of experimental studies about the force of internal solitary wave and internal periodic wave on vertical cylinders have been carried out in a two-dimensional layered internal wave flume. The internal solitary waves are produced by means of gravitational collapse at the layer thickness ratio of 0.2, and the internal periodic waves are produced with rocker-flap wave maker at the layer thickness ratio of 0.93. The wave parameters are obtained through dyeing photography. The vertical cylinders of the same size are arranged in different depths. The horizontal force on each cylinder is measured and the vertical distribution rules are researched. The internal wave heights are changed to study the impact of wave heights on the force. The results show that the horizontal force of concave type internal solitary wave on vertical cylinder in the upper-layer fluid has the same direction as the wave propagating, while it has an opposite direction in the lower-layer. The horizontal force is not evenly distributed in the lower fluid. And the force at different depths increases along with wave height. Internal solitary wave can produce an impact load on the entire pile. The horizontal force of internal periodic waves on the vertical cylinders is periodically changed at the frequency of waves. The direction of the force is opposite in the upper and lower layers, and the value is close. In the upper layer except the depth close to the interface, the force is evenly distributed; but it tends to decrease with the deeper depth in the lower layer. A periodic shear load can be produced on the entire pile by internal periodic waves, and it may cause fatigue damage to structures.
文摘Due to increasing pressure on brand owners and distributors to avoid single use plastics such as plastic bundle packaging, a new bundle packaging that consists of corrugated board only, has been designed. Obviously this new packaging should equally enable transportability. This study compares the transportability of bundles using corrugated board on the one hand and bundles using plastic collation shrink film on the other. In particular, the resistance to varying horizontal inertial forces is compared experimentally. All tested bundle packagings of corrugated board perform well above expectations and significantly better than shrink film packaging. All additional requirements regarding marketing, durability, consumer convenience, …are met.
文摘A dual-baffled rectangular tank with different configurations is proposed to reduce the sloshing effect,and design optimization is conducted through numerical simulations with open-source software,namely OpenFOAM,based on the computational fluid dynamic model.A series of physical experiments in the dual-baffled rectangular tank is performed for model validation and design optimization with the measured water surface elevation distributions along the tank.The optimization uses the calculated maximum horizontal force exerted on the tank and entropy generation(EG)as the criterion.Results show that the dual-baffle configuration positioned at the tank center is more effective in reducing the sloshing than that of the single baffle when the relative baffle height and initial water depth ratio(Hb/Hw,where Hb and Hw represent baffle height and static water depth,respectively)are larger than 0.5.However,such an effect then diminishes when the ratio is larger than 0.75.The effect of the dual-baffle configuration on the sway motion under the condition of different motion amplitudes and frequencies is also evaluated.The results show that the reduction in the maximum horizontal force is almost the same for dual-and single-baffled configurations and reaches the minimum when the sway motion amplitude is near 0.03 m.The dual-baffled configuration for the angular frequency of the sway motion is more effective than the single-baffled in reducing the sloshing at the low angular frequencies but is only less effective at high angular frequencies.Furthermore,the optimal baffle inclination angle is 85°when the inclined straight and curved baffles are used,and curved baffles can successfully decrease the horizontal force exerted on the tank and EG.
文摘Using linear water wave theory,three-dimensional problems concerning the interaction of waves with spherical structures in a fluid which contains a three-layer fluid consisting of a layer of finite depth bounded above by freshwater of finite depth with free surface and below by an infinite layer of water of greater density are considered.In such a situation timeharmonic waves with a given frequency can propagate with three wavenumbers.The sphere is submerged in either of the three layers.Each problem is reduced to an infinite system of linear equations by employing the method of multipoles and the system of equations is solved numerically by standard technique.The hydrodynamic forces(vertical and horizontal forces)are obtained and depicted graphically against the wavenumber.When the density ratio of the upper and middle layer is made to approximately one,curves for vertical and horizontal forces almost coincide with the corresponding curves for the case of a two-layer fluid with a free surface.This means that in the limit,the density ratio of the upper and middle layer goes to approximately one,the solution agrees with the solution for the case of a two-layer fluid with a free surface.
基金financially supported by the General Program of the National Natural Science Foundation of China(Grant No.51979192)the National Key Rsearch and Development Program of China(Grant Nos.2020YFE0201200 and 2021YFB2600700)the Program of China Communications Construction Company Limited(Grant No.2018-ZJKJ-01).
文摘The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs have been so far restricted to the water level above the bottom of the superstructure,which mainly occurs under the high tides or storm tides.However,based on recent engineering applications and experimental observations,the most severe conditions for CTBs are more likely to occur under a medium water level,because impulsive wave pressure may occur due to interactions between waves and the special chamber in CTBs.Meanwhile,during the most of construction and operation periods,the CTBs are mainly working under the medium water levels,i.e.,water levels below the bottom of the superstructure.In this study,the effects of main influence parameters on the horizontal wave force coefficient and wave transmission coefficient for open CTBs(with partially immersed side plates)under medium water levels were investigated based on a 3D numerical wave flume and corresponding empirical formulae were proposed.It is indicated that the location of the side plate related to the main caisson has significant influence on the hydrodynamic performance of CTBs.In engineering applications,the location of the side plate can be designed at b/L≤0.15 or b/L≥0.3(where b is the distance between the side plate and the front face of the main caisson and L is the incident wave length)for efficiently lowering the horizontal wave force and wave transmission.The flow mechanism of impulsive wave force on CTBs was revealed based on synchronous analyses of flow fields and pressure distribution.Through appropriate design of the height of the superstructure according to H/hD≤1.0 or H/hD≥1.5(where H is the incident wave height and hD is the distance between the still water level and the bottom of the superstructure),the likely impulsive wave pressure on the side plate can also be diminished.
