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
In order to get the formulae for calculating the equivalent frame width coefficient of reinforced concrete hollow slab-column structures with edge beam,the finite element structural program was used in the elastic ana...In order to get the formulae for calculating the equivalent frame width coefficient of reinforced concrete hollow slab-column structures with edge beam,the finite element structural program was used in the elastic analysis of reinforced concrete hollow slab-column structure with different dimensions to study internal relationship between effective beam width and the frame dimensions.In addition,the formulas for calculating the increasing coefficient of edge beam were also obtained.展开更多
A novel periodic mount was presented. A theoretical model was developed to describe the dynamics of wave propagation in the novel periodic mount. The model was derived using Hamilton's energy conservation principl...A novel periodic mount was presented. A theoretical model was developed to describe the dynamics of wave propagation in the novel periodic mount. The model was derived using Hamilton's energy conservation principle. The characteristics of wave propagation in unit cell were analyzed by transfer matrix formulation. Numerical examples were given to illustrate the effectiveness of the periodic mount. The experiments were carried out to identify the predications of the theoretical model. The obtained results show that the experimental results coincide with the prediction of theoretical model. No pass bands appear in the overall frequency range measured when waves propagate in the longitude direction of the periodic mount. These dramatic results demonstrate its potential as an excellent mount in attenuating and isolating vibration transmission.展开更多
In order to study an isolation system of rolling friction with springs, computer programs were compiled to evaluate the seismic performance based on its movement characteristics. Through the programs, the influences o...In order to study an isolation system of rolling friction with springs, computer programs were compiled to evaluate the seismic performance based on its movement characteristics. Through the programs, the influences of various seismic performance factors, e.g., rolling friction coefficient, spring constant, were systematically investigated. Results show that by increasing the rolling friction coefficient, the structural relative displacement due to seismic load effectively decreases, while the structural response magnitude varies mainly depending on the correlations between the following factors: the spring constant, the earthquake intensity, and the rolling friction coefficient. Furthermore, increasing the spring constant can decrease the structural relative displacement, as well as residual displacement, however, it increases the structural response magnitude. Finally, based on the analyses of various seismic performance factors subjected to the scenario earthquakes, optimized theoretical seismic performance can be achieved by reasonably combining the spring constant and the rolling friction coefficient.展开更多
The purpose of this paper is to discuss the suitability of out-of-codes tall slab-column and shearwall structure and to popularize the structure in seismic region.In the research,flat-plate floor was used in slab-colu...The purpose of this paper is to discuss the suitability of out-of-codes tall slab-column and shearwall structure and to popularize the structure in seismic region.In the research,flat-plate floor was used in slab-column and shearwall structure in the practical engineering,the key parameters of slab-column and shearwall structure and frame-shearwall structure such as deflection,punching shear behavior,story drift and capability curve were worked out by static plastic analysis,elastic-plastic time history analysis and pushover analysis,then the suitability of out-of-codes tall slab-column and shearwall structure was evaluated.The results show that the out-of-codes tall slab-column and shearwall structure studies could satisfy the require of deflection and punching shear behavior,the story drift under 7 degree expected rare earthquake waves could satisfy the limit value in the codes and the seismic design spectrum was crossed by the capability curve of the structure and the structure could not collapse.The conclusion is that slab-column and shearwall structure with reasonable design built in Ⅱ soil site of intensity 7 seismic fortification zone can be designed higher than the limit height in the codes.展开更多
Aimed at the problem of classification of non-hydrocarbons of crude oil, the theoretical standpoint that the polarity of a compound depends on the whole structure and composition of molecule instead of a kind of heter...Aimed at the problem of classification of non-hydrocarbons of crude oil, the theoretical standpoint that the polarity of a compound depends on the whole structure and composition of molecule instead of a kind of heteroatom or its functional group was presented. A method was established for the systematically structural identification of nitric compounds in crude oil. The pre-fractionation of a crude oil sample into 7 fractions was performed by di- adsorption column chromatography with neutral aluminum oxide and silica gel. Subsequently, the individual components were obtained by using capillary column gas chromatography, and the types of compounds were detected by a mass spectrometer. In combination with a chemometric resolution, the compounds of fraction were further identified. This method can relieve the difficulty of classical analysis in identifying those species with very low contents or without being completely separated. The structures of 168 nitric compounds in a crude oil sample were determined by this method.展开更多
Enhanced boiling experiments of two different enhanced structures were carried out in a thermosyphon loop evaporator chamber. One was micro-columns array structure (MCAS), which was fabricated on copper plate surface ...Enhanced boiling experiments of two different enhanced structures were carried out in a thermosyphon loop evaporator chamber. One was micro-columns array structure (MCAS), which was fabricated on copper plate surface with interaction high speed wire electrode discharge machining (HS-WEDM). The other was the ramification of MCAS, named micro-column-array and sintered-copper compound structure (MSCS), which was fabricated with sintered method on micro-column array structure. Considering the wall superheat and critical heat flux (CHF), comparisons were made between them. The results show that both MCAS and MSCS can enhance the boiling heat transfer. It is also found that the enhanced boiling heat transfer ability of MSCS is changed obviously while the porosity of the sintered copper layer is changed.展开更多
This paper put forward a new-type vortex generator enhancing heat exchange of solar air-drier and air-heater on the gas side,and investigated the mechanism of heat transfer enhancement and drag reduction by the influe...This paper put forward a new-type vortex generator enhancing heat exchange of solar air-drier and air-heater on the gas side,and investigated the mechanism of heat transfer enhancement and drag reduction by the influence of vortex generators on the coherent structure of turbulent boundary layer.The flow and heat transfer characteristics of rectangle channel with bevel-cut half-elliptical column vortex generators were obtained using large eddy simulation(LES)and the hydromechanics software FLUENT6.3.The instantaneous properties of velocity,temperature and pressure in channel were gained.The coherent structure of turbulent boundary layer flow was showed,and the characteristic of vortex induced by inclined-cut semi-ellipse vortex generator and its influence on turbulent coherent structure were analyzed.And the effect mechanism of turbulent coherent structure on flow field,pressure field and temperature field was discussed.Based on the results,the heat transfer coefficient and drag reduction of the new vortex generator with different pitch angles were compared.Sometimes,the coherent effects of the increased wall heat transfer and the decreased skin friction do not satisfy the Reynolds analogy.The turbulent coherent structure can be controlled through the geometry of the vortex generator,so the heat transfer and drag reduction can also be controlled.Then we can seek suitable form of vortex generator and structure parameters,in order to achieve the enhanced heat transfer and flow of drag reduction in the solar air-heater and solar air-drier.展开更多
By taking a rolling-spring isolation system as the study object, the effects of the non-uniform distribution of rolling friction coefficient on its isolation performance were analyzed by a compiled computer program. T...By taking a rolling-spring isolation system as the study object, the effects of the non-uniform distribution of rolling friction coefficient on its isolation performance were analyzed by a compiled computer program. The results show that the errors associated with the structural maximum relative displacement, acceleration and residual displacement due to ignoring the friction variability sequentially grow. This rule is weakened by the spring action, however, the unreasonable spring constant will cause sympathetic vibration. Under the condition of large friction variability, in the calculation of the structural maximum relative displacement and acceleration, the friction variability should be considered. When the structural residual displacement is concerned, the variability of rolling friction coefficient should be fully considered regardless of the friction variability.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.
文摘In order to get the formulae for calculating the equivalent frame width coefficient of reinforced concrete hollow slab-column structures with edge beam,the finite element structural program was used in the elastic analysis of reinforced concrete hollow slab-column structure with different dimensions to study internal relationship between effective beam width and the frame dimensions.In addition,the formulas for calculating the increasing coefficient of edge beam were also obtained.
基金Project(50775225) supported by the National Natural Science Foundation of China
文摘A novel periodic mount was presented. A theoretical model was developed to describe the dynamics of wave propagation in the novel periodic mount. The model was derived using Hamilton's energy conservation principle. The characteristics of wave propagation in unit cell were analyzed by transfer matrix formulation. Numerical examples were given to illustrate the effectiveness of the periodic mount. The experiments were carried out to identify the predications of the theoretical model. The obtained results show that the experimental results coincide with the prediction of theoretical model. No pass bands appear in the overall frequency range measured when waves propagate in the longitude direction of the periodic mount. These dramatic results demonstrate its potential as an excellent mount in attenuating and isolating vibration transmission.
基金Project(51308549)supported by the National Natural Science Foundation,China
文摘In order to study an isolation system of rolling friction with springs, computer programs were compiled to evaluate the seismic performance based on its movement characteristics. Through the programs, the influences of various seismic performance factors, e.g., rolling friction coefficient, spring constant, were systematically investigated. Results show that by increasing the rolling friction coefficient, the structural relative displacement due to seismic load effectively decreases, while the structural response magnitude varies mainly depending on the correlations between the following factors: the spring constant, the earthquake intensity, and the rolling friction coefficient. Furthermore, increasing the spring constant can decrease the structural relative displacement, as well as residual displacement, however, it increases the structural response magnitude. Finally, based on the analyses of various seismic performance factors subjected to the scenario earthquakes, optimized theoretical seismic performance can be achieved by reasonably combining the spring constant and the rolling friction coefficient.
文摘The purpose of this paper is to discuss the suitability of out-of-codes tall slab-column and shearwall structure and to popularize the structure in seismic region.In the research,flat-plate floor was used in slab-column and shearwall structure in the practical engineering,the key parameters of slab-column and shearwall structure and frame-shearwall structure such as deflection,punching shear behavior,story drift and capability curve were worked out by static plastic analysis,elastic-plastic time history analysis and pushover analysis,then the suitability of out-of-codes tall slab-column and shearwall structure was evaluated.The results show that the out-of-codes tall slab-column and shearwall structure studies could satisfy the require of deflection and punching shear behavior,the story drift under 7 degree expected rare earthquake waves could satisfy the limit value in the codes and the seismic design spectrum was crossed by the capability curve of the structure and the structure could not collapse.The conclusion is that slab-column and shearwall structure with reasonable design built in Ⅱ soil site of intensity 7 seismic fortification zone can be designed higher than the limit height in the codes.
文摘Aimed at the problem of classification of non-hydrocarbons of crude oil, the theoretical standpoint that the polarity of a compound depends on the whole structure and composition of molecule instead of a kind of heteroatom or its functional group was presented. A method was established for the systematically structural identification of nitric compounds in crude oil. The pre-fractionation of a crude oil sample into 7 fractions was performed by di- adsorption column chromatography with neutral aluminum oxide and silica gel. Subsequently, the individual components were obtained by using capillary column gas chromatography, and the types of compounds were detected by a mass spectrometer. In combination with a chemometric resolution, the compounds of fraction were further identified. This method can relieve the difficulty of classical analysis in identifying those species with very low contents or without being completely separated. The structures of 168 nitric compounds in a crude oil sample were determined by this method.
基金Projects(50605023 50436010) supported by the National Natural Science Foundation of China
文摘Enhanced boiling experiments of two different enhanced structures were carried out in a thermosyphon loop evaporator chamber. One was micro-columns array structure (MCAS), which was fabricated on copper plate surface with interaction high speed wire electrode discharge machining (HS-WEDM). The other was the ramification of MCAS, named micro-column-array and sintered-copper compound structure (MSCS), which was fabricated with sintered method on micro-column array structure. Considering the wall superheat and critical heat flux (CHF), comparisons were made between them. The results show that both MCAS and MSCS can enhance the boiling heat transfer. It is also found that the enhanced boiling heat transfer ability of MSCS is changed obviously while the porosity of the sintered copper layer is changed.
基金Supported by National Natural Science Foundation of China(50676027)
文摘This paper put forward a new-type vortex generator enhancing heat exchange of solar air-drier and air-heater on the gas side,and investigated the mechanism of heat transfer enhancement and drag reduction by the influence of vortex generators on the coherent structure of turbulent boundary layer.The flow and heat transfer characteristics of rectangle channel with bevel-cut half-elliptical column vortex generators were obtained using large eddy simulation(LES)and the hydromechanics software FLUENT6.3.The instantaneous properties of velocity,temperature and pressure in channel were gained.The coherent structure of turbulent boundary layer flow was showed,and the characteristic of vortex induced by inclined-cut semi-ellipse vortex generator and its influence on turbulent coherent structure were analyzed.And the effect mechanism of turbulent coherent structure on flow field,pressure field and temperature field was discussed.Based on the results,the heat transfer coefficient and drag reduction of the new vortex generator with different pitch angles were compared.Sometimes,the coherent effects of the increased wall heat transfer and the decreased skin friction do not satisfy the Reynolds analogy.The turbulent coherent structure can be controlled through the geometry of the vortex generator,so the heat transfer and drag reduction can also be controlled.Then we can seek suitable form of vortex generator and structure parameters,in order to achieve the enhanced heat transfer and flow of drag reduction in the solar air-heater and solar air-drier.
基金Projects(51308549,51378504,51478475) supported by the National Natural Science Foundation of ChinaProject(2015JJ3159) supported by the Natural Science Foundation of Hunan Province,ChinaProject(2015CX006) supported by the Innovation-driven Plan in Central South University,China
文摘By taking a rolling-spring isolation system as the study object, the effects of the non-uniform distribution of rolling friction coefficient on its isolation performance were analyzed by a compiled computer program. The results show that the errors associated with the structural maximum relative displacement, acceleration and residual displacement due to ignoring the friction variability sequentially grow. This rule is weakened by the spring action, however, the unreasonable spring constant will cause sympathetic vibration. Under the condition of large friction variability, in the calculation of the structural maximum relative displacement and acceleration, the friction variability should be considered. When the structural residual displacement is concerned, the variability of rolling friction coefficient should be fully considered regardless of the friction variability.
