Seismic isolation effectively reduces seismic demands on building structures by isolating the superstructure from ground vibrations during earthquakes.However,isolation strategies give less attention to acceleration-s...Seismic isolation effectively reduces seismic demands on building structures by isolating the superstructure from ground vibrations during earthquakes.However,isolation strategies give less attention to acceleration-sensitive systems or equipment.Meanwhile,as the isolation layer’s displacement grows,the stiffness and frequency of traditional rolling and sliding isolation bearings increases,potentially causing self-centering and resonance concerns.As a result,a new conical pendulum bearing has been selected for acceleration-sensitive equipment to increase self-centering capacity,and additional viscous dampers are incorporated to enhance system damping.Moreover,the theoretical formula for conical pendulum bearings is supplied to analyze the device’s dynamic parameters,and shake table experiments are used to determine the proposed device’s isolation efficiency under various conditions.According to the test results,the newly proposed devices have remarkable isolation performance in terms of minimizing both acceleration and displacement responses.Finally,a numerical model of the isolation system is provided for further research,and the accuracy is demonstrated by the aforementioned experiments.展开更多
Precise analysis of the floor acceleration amplification(FAA)factor is crucial for accurately predicting the acceleration on acceleration-sensitive nonstructural components and estimating the seismic safety of nonstru...Precise analysis of the floor acceleration amplification(FAA)factor is crucial for accurately predicting the acceleration on acceleration-sensitive nonstructural components and estimating the seismic safety of nonstructural components.However,the existing literature on FAA did not analyze various influencing factors quantitatively.For solving this problem,one novel quantitative analyzing method of FAA considering various influencing factors in terms of structural type,structural height,site category,structural period,relative height and ground motion intensity based on instrumented buildings data from the Center for Engineering Strong Motion Data(CESMD)is proposed.The analysis results revealed that the site categories can significantly affect the FAA values of various types of structures,however,which has not been emphasized in previous studies.Correlation analysis reveals that the relative height is strongly correlated with the FAA,which is consistent with several seismic design codes.While,the parameters in terms of the site category,structural height and structural type also significantly correlated with the FAA.The results indicate that these three factors should be incorporated into the seismic design code.This study offers valuable insights and recommendations for the design of acceleration-sensitive nonstructural components in terms of FAA.展开更多
基金Scientific Research Fund of Institute of Engineering Mechanics,CEA under Grant No.2019A03Scientific Research Fund of Institute of Engineering Mechanics,CEA under Grant No.2021D12National Key R&D Program of China under No.2018YFC1504404。
文摘Seismic isolation effectively reduces seismic demands on building structures by isolating the superstructure from ground vibrations during earthquakes.However,isolation strategies give less attention to acceleration-sensitive systems or equipment.Meanwhile,as the isolation layer’s displacement grows,the stiffness and frequency of traditional rolling and sliding isolation bearings increases,potentially causing self-centering and resonance concerns.As a result,a new conical pendulum bearing has been selected for acceleration-sensitive equipment to increase self-centering capacity,and additional viscous dampers are incorporated to enhance system damping.Moreover,the theoretical formula for conical pendulum bearings is supplied to analyze the device’s dynamic parameters,and shake table experiments are used to determine the proposed device’s isolation efficiency under various conditions.According to the test results,the newly proposed devices have remarkable isolation performance in terms of minimizing both acceleration and displacement responses.Finally,a numerical model of the isolation system is provided for further research,and the accuracy is demonstrated by the aforementioned experiments.
基金National Natural Science Foundation of China under Grant Nos.52278173,52378150 and 52078398Foundation of Key Laboratory of Structures Dynamic Behavior and Control(Ministry of Education)in Harbin Institute of Technology under Grant No.HITCE202008。
文摘Precise analysis of the floor acceleration amplification(FAA)factor is crucial for accurately predicting the acceleration on acceleration-sensitive nonstructural components and estimating the seismic safety of nonstructural components.However,the existing literature on FAA did not analyze various influencing factors quantitatively.For solving this problem,one novel quantitative analyzing method of FAA considering various influencing factors in terms of structural type,structural height,site category,structural period,relative height and ground motion intensity based on instrumented buildings data from the Center for Engineering Strong Motion Data(CESMD)is proposed.The analysis results revealed that the site categories can significantly affect the FAA values of various types of structures,however,which has not been emphasized in previous studies.Correlation analysis reveals that the relative height is strongly correlated with the FAA,which is consistent with several seismic design codes.While,the parameters in terms of the site category,structural height and structural type also significantly correlated with the FAA.The results indicate that these three factors should be incorporated into the seismic design code.This study offers valuable insights and recommendations for the design of acceleration-sensitive nonstructural components in terms of FAA.
