Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs ar...Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs are built under earthquake excitations, and parametrical optimization for multimodal control is carried out under excitations of harmonic ground motion. An 11 story frame building controlled by MTMDs is simulated under the excitation of El Centro earthquake (1940, NS), and its displacement response at the top floor in the case of multimodal control is reduced by 20% more than the case of single modal control. Some conclusions are given as the MTMDs is an effective, reliable and practical passive measurement for controlling seismic responses of tall buildings and the multimodal control has better adaptability and reliability by comparison with the single modal control.展开更多
A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of ...A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of high time cost in adopting a rational-based optimal design method for ship structural design. Furthermore,the method was verified by its effective application in optimization of the mid-ship section of a container ship. A full 3-D FEM model of a ship,suffering static and quasi-static loads, was used as the analyzing object for evaluating the structural performance of the mid-ship module, including static strength and buckling performance. Research results reveal that this new method could substantially reduce the computational cost of the rational-based optimization problem without decreasing its accuracy, which increases the feasibility and economic efficiency of using a rational-based optimal design method in ship structural design.展开更多
The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. Thi...The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities （aerobics）. The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS （root mean square） accelerations and VDV （vibration dose value） values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.展开更多
Growth of an anthropogenic load on an environment in the second halfofXXth centuries has led to an exacerbation of many ecological problems. Today ecological risk scales cover territories of large regions. In this res...Growth of an anthropogenic load on an environment in the second halfofXXth centuries has led to an exacerbation of many ecological problems. Today ecological risk scales cover territories of large regions. In this respect the territory of Azerbaijan is not exception, within which Baku is noted by very adverse ecological conditions. Complex natural conditions （presence of strong winds, high air temperature and solar radiation） complicate the city ecological situation even greater. In modem conditions a construction boom relates to the factors aggravating the ecological situation of Baku. Last 10 years the city is rapidly built on by multistoried buildings which deform it, hinder visual contacts to the environment and obstruct the natural aeration of Baku amphitheater. The modem multistoried buildings erected ignoring town-planning norms do not correspond with regional climatic conditions, essentially modify the territory wind regime, hamper in surrounding buildings insolation, neglect a territory temperature-humidity conditions. As a result, it is necessary to use energy overly for their adaptation to Baku conditions and creation comfortable microclimate in them that leads to the city environmental pollution. The planning decisions and construction materials applied in these buildings are also alien to Baku climatic conditions. For qualitative transformation of Baku environment and improvement of ecological characteristics of the residential areas the author has carried out the estimation of the city territory on a complex of climatic factors （aeration, insolation and thermal-humidity regimes）. For these purposes the multidimensional statistical method is used. As a result the investigated territory of Baku is divided into 5 typological areas on climatic conditions. The brief characteristic and the general recommendations on transformation are worked out by the author for each of these typological units. Results of the research can be a basis for revealing of methods and principles of town-planning and architectural-planning organization of Baku residential areas.展开更多
Based on simulated material scale modeling and numerical simulation, the protective seam mining method was conducted at one coal mine. After extracting the No.15seam, the overlying strata movement and the deformation ...Based on simulated material scale modeling and numerical simulation, the protective seam mining method was conducted at one coal mine. After extracting the No.15seam, the overlying strata movement and the deformation of the No.9-10 protected seamwere studied. The experiment results show that it is feasible to destress the protectedseams with large interburden thickness. When the face had advanced 200 m from thesetup room, the No.9-10 seam was fully destressed, resulting in easy gas drainage in thedestressed zone. Recommendations on mining sequence of multiple seams mining in thesame coal areas were made.展开更多
Water and heat dynamics in the active layer at a monitoring site in the Tanggula Mountains, located in the permafrost region of the Qinghai-Xizang （Tibet） Plateau （QXP）, were studied using the physical-process-bas...Water and heat dynamics in the active layer at a monitoring site in the Tanggula Mountains, located in the permafrost region of the Qinghai-Xizang （Tibet） Plateau （QXP）, were studied using the physical-process-based COUPMODEL model, including the interaction between soil temperature and moisture under freeze-thaw cycles. Meteorological, ground temperature and moisture data from different depths within the active layer were used to calibrate and validate the model. The results indicate that the calibrated model satisfactorily simulates the soil temperatures from the top to the bottom of the soil layers as well as the moisture content of the active layer in permafrost regions. The simulated soil heat flux at depths of 0 to 20 cm was consistent with the monitoring data, and the simulations of the radiation balance components were reasonable. Energy consumed for phase change was estimated from the simulated ice content during the freeze/thaw processes from 2007 to 2008. Using this model, the active layer thickness and the energy consumed for phase change were predicted for future climate warming scenarioS. The model predicts an increase of the active layer thickness from the current 330 cm to approximately 350-390 cm as a result of a 1-2℃ warming. However, the effect active layer thickness of more precipitation is limited when the precipitation is increased by 20%-50%. The COUPMODEL provides a useful tool for predicting and understanding the fate of permafrost in the QXP under a warming climate.展开更多
This paper provides a survey of local refinable splines,including hierarchical B-splines,T-splines,polynomial splines over T-meshes,etc.,with a view to applications in geometric modeling and iso-geometric analysis.We ...This paper provides a survey of local refinable splines,including hierarchical B-splines,T-splines,polynomial splines over T-meshes,etc.,with a view to applications in geometric modeling and iso-geometric analysis.We will identify the strengths and weaknesses of these methods and also offer suggestions for their using in geometric modeling and iso-geometric analysis.展开更多
文摘Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs are built under earthquake excitations, and parametrical optimization for multimodal control is carried out under excitations of harmonic ground motion. An 11 story frame building controlled by MTMDs is simulated under the excitation of El Centro earthquake (1940, NS), and its displacement response at the top floor in the case of multimodal control is reduced by 20% more than the case of single modal control. Some conclusions are given as the MTMDs is an effective, reliable and practical passive measurement for controlling seismic responses of tall buildings and the multimodal control has better adaptability and reliability by comparison with the single modal control.
基金Supported by the Project of Ministry of Education and Finance(No.200512)the Project of the State Key Laboratory of ocean engineering(GKZD010053-10)
文摘A new multi-level analysis method of introducing the super-element modeling method, derived from the multi-level analysis method first proposed by O. F. Hughes, has been proposed in this paper to solve the problem of high time cost in adopting a rational-based optimal design method for ship structural design. Furthermore,the method was verified by its effective application in optimization of the mid-ship section of a container ship. A full 3-D FEM model of a ship,suffering static and quasi-static loads, was used as the analyzing object for evaluating the structural performance of the mid-ship module, including static strength and buckling performance. Research results reveal that this new method could substantially reduce the computational cost of the rational-based optimization problem without decreasing its accuracy, which increases the feasibility and economic efficiency of using a rational-based optimal design method in ship structural design.
文摘The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities （aerobics）. The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS （root mean square） accelerations and VDV （vibration dose value） values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.
文摘Growth of an anthropogenic load on an environment in the second halfofXXth centuries has led to an exacerbation of many ecological problems. Today ecological risk scales cover territories of large regions. In this respect the territory of Azerbaijan is not exception, within which Baku is noted by very adverse ecological conditions. Complex natural conditions （presence of strong winds, high air temperature and solar radiation） complicate the city ecological situation even greater. In modem conditions a construction boom relates to the factors aggravating the ecological situation of Baku. Last 10 years the city is rapidly built on by multistoried buildings which deform it, hinder visual contacts to the environment and obstruct the natural aeration of Baku amphitheater. The modem multistoried buildings erected ignoring town-planning norms do not correspond with regional climatic conditions, essentially modify the territory wind regime, hamper in surrounding buildings insolation, neglect a territory temperature-humidity conditions. As a result, it is necessary to use energy overly for their adaptation to Baku conditions and creation comfortable microclimate in them that leads to the city environmental pollution. The planning decisions and construction materials applied in these buildings are also alien to Baku climatic conditions. For qualitative transformation of Baku environment and improvement of ecological characteristics of the residential areas the author has carried out the estimation of the city territory on a complex of climatic factors （aeration, insolation and thermal-humidity regimes）. For these purposes the multidimensional statistical method is used. As a result the investigated territory of Baku is divided into 5 typological areas on climatic conditions. The brief characteristic and the general recommendations on transformation are worked out by the author for each of these typological units. Results of the research can be a basis for revealing of methods and principles of town-planning and architectural-planning organization of Baku residential areas.
基金Supported by Ministry of Education Doctoral Foundation (20070460001)Natural Science Foundation of Henan Province (0623021400)
文摘Based on simulated material scale modeling and numerical simulation, the protective seam mining method was conducted at one coal mine. After extracting the No.15seam, the overlying strata movement and the deformation of the No.9-10 protected seamwere studied. The experiment results show that it is feasible to destress the protectedseams with large interburden thickness. When the face had advanced 200 m from thesetup room, the No.9-10 seam was fully destressed, resulting in easy gas drainage in thedestressed zone. Recommendations on mining sequence of multiple seams mining in thesame coal areas were made.
基金financially supported by the National Major Scientific Project of China(Grant No.2013CBA01803)the National Natural Science Foundation of China(Grant Nos.41271081+1 种基金41271086)the Foundation of One Hundred Person Project of the Chinese Academy of Sciences(Grant No.51Y551831)
文摘Water and heat dynamics in the active layer at a monitoring site in the Tanggula Mountains, located in the permafrost region of the Qinghai-Xizang （Tibet） Plateau （QXP）, were studied using the physical-process-based COUPMODEL model, including the interaction between soil temperature and moisture under freeze-thaw cycles. Meteorological, ground temperature and moisture data from different depths within the active layer were used to calibrate and validate the model. The results indicate that the calibrated model satisfactorily simulates the soil temperatures from the top to the bottom of the soil layers as well as the moisture content of the active layer in permafrost regions. The simulated soil heat flux at depths of 0 to 20 cm was consistent with the monitoring data, and the simulations of the radiation balance components were reasonable. Energy consumed for phase change was estimated from the simulated ice content during the freeze/thaw processes from 2007 to 2008. Using this model, the active layer thickness and the energy consumed for phase change were predicted for future climate warming scenarioS. The model predicts an increase of the active layer thickness from the current 330 cm to approximately 350-390 cm as a result of a 1-2℃ warming. However, the effect active layer thickness of more precipitation is limited when the precipitation is increased by 20%-50%. The COUPMODEL provides a useful tool for predicting and understanding the fate of permafrost in the QXP under a warming climate.
基金supported by National Natural Science Foundation of China(Grant Nos.11031007 and 60903148)the Chinese Universities Scientific Fund+2 种基金Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry,the Chinese Academy of Sciences Startup Scientific Research Foundationthe State Key Development Program for Basic Research of China(973 Program)(Grant No.2011CB302400)
文摘This paper provides a survey of local refinable splines,including hierarchical B-splines,T-splines,polynomial splines over T-meshes,etc.,with a view to applications in geometric modeling and iso-geometric analysis.We will identify the strengths and weaknesses of these methods and also offer suggestions for their using in geometric modeling and iso-geometric analysis.
