This study proposes a micro vibration mitigation system using viscous dampers to solve the problem of vibration in a high-tech building. Due to the operating frequency of the air conditioners and fundamental mode of t...This study proposes a micro vibration mitigation system using viscous dampers to solve the problem of vibration in a high-tech building. Due to the operating frequency of the air conditioners and fundamental mode of the floors, a resonant phenomenon is occasionally experienced at the upper levels of the structure. Several strategies were considered, and viscous dampers combined with a suspension system were chosen to mitigate this annoying situation. A theoretical analysis was first executed to determine the optimal design value of the damper and the suspension spring. An efficient reduction in floor velocity of approximately 50 % was achieved by the proposed system. Practical verifications including a performance test of the micro-vibration-oriented dampers, the pragmatic application result, and a comparison in one-third octave spectrum was then carried out. The performance of the system was demonstrated by the data measured. It alleviated more trembling than was numerically expected. The energy absorbed by the viscous dampers is illustrated by the hysteresis loops and the one-third octave spectrum. It is found that with the proposed system, the vibration can be effectively captured by the viscous damper and converted to lower frequency-content tremors. The success of this project greatly supports the proposed standard two-stage analysis procedure for mitigating micro-vibration problems in practice. This research extends the use of viscous dampers to a new field.展开更多
To solve the safe horizontal transportation by rail&road of remote sensing satellite problem in the process of unpredictable dynamic load,a high attenuation vibration isolation damper(hereinafter referred to as vi...To solve the safe horizontal transportation by rail&road of remote sensing satellite problem in the process of unpredictable dynamic load,a high attenuation vibration isolation damper(hereinafter referred to as vibration isolation damper)was developed.By simulation analysis and transportation test using satellite structural model and engineering prototype,validity and reliability of the vibration isolation damper was verified,which can meet the requirements of vibration and shock from various transportation conditions.展开更多
A cantilever beam with Damping Material Applying Rubber Magnetic Powder （DRM） has been investigated. Two methods are selected to hold DRM to a vibrating steel beam, one is to attach DRM by the magnetic attractive fo...A cantilever beam with Damping Material Applying Rubber Magnetic Powder （DRM） has been investigated. Two methods are selected to hold DRM to a vibrating steel beam, one is to attach DRM by the magnetic attractive force （called DRM beam） and the other by adhesive bonding （called AB-DRM beam）. Different from the damping property of AB-DRM beam caused by shear deformation of damping material, the damping property of DRM beam is characterized by the sliding frictional loss together with the internal loss of damping material. The authors established a formulation to predict the damping characteristics of DRM beam, which was validated experimentally. It is found that rubber material loss factor β has a decisive influence on damping improvement of DRM beam versus AB-DRM beam. If β is smaller than the critical value around 0.8255, a valid range of vibratory amplitude always exists in which DRM beam can achieve better damping than AB-DRM beam; conversely, if β is bigger than the critical value, the valid range does not exist when slide occurs. Such results are used to determine the merits and limitations of DRM and develop design guidelines.展开更多
文摘This study proposes a micro vibration mitigation system using viscous dampers to solve the problem of vibration in a high-tech building. Due to the operating frequency of the air conditioners and fundamental mode of the floors, a resonant phenomenon is occasionally experienced at the upper levels of the structure. Several strategies were considered, and viscous dampers combined with a suspension system were chosen to mitigate this annoying situation. A theoretical analysis was first executed to determine the optimal design value of the damper and the suspension spring. An efficient reduction in floor velocity of approximately 50 % was achieved by the proposed system. Practical verifications including a performance test of the micro-vibration-oriented dampers, the pragmatic application result, and a comparison in one-third octave spectrum was then carried out. The performance of the system was demonstrated by the data measured. It alleviated more trembling than was numerically expected. The energy absorbed by the viscous dampers is illustrated by the hysteresis loops and the one-third octave spectrum. It is found that with the proposed system, the vibration can be effectively captured by the viscous damper and converted to lower frequency-content tremors. The success of this project greatly supports the proposed standard two-stage analysis procedure for mitigating micro-vibration problems in practice. This research extends the use of viscous dampers to a new field.
文摘To solve the safe horizontal transportation by rail&road of remote sensing satellite problem in the process of unpredictable dynamic load,a high attenuation vibration isolation damper(hereinafter referred to as vibration isolation damper)was developed.By simulation analysis and transportation test using satellite structural model and engineering prototype,validity and reliability of the vibration isolation damper was verified,which can meet the requirements of vibration and shock from various transportation conditions.
基金the National Natural Science Foundation of China (No.10472035).
文摘A cantilever beam with Damping Material Applying Rubber Magnetic Powder （DRM） has been investigated. Two methods are selected to hold DRM to a vibrating steel beam, one is to attach DRM by the magnetic attractive force （called DRM beam） and the other by adhesive bonding （called AB-DRM beam）. Different from the damping property of AB-DRM beam caused by shear deformation of damping material, the damping property of DRM beam is characterized by the sliding frictional loss together with the internal loss of damping material. The authors established a formulation to predict the damping characteristics of DRM beam, which was validated experimentally. It is found that rubber material loss factor β has a decisive influence on damping improvement of DRM beam versus AB-DRM beam. If β is smaller than the critical value around 0.8255, a valid range of vibratory amplitude always exists in which DRM beam can achieve better damping than AB-DRM beam; conversely, if β is bigger than the critical value, the valid range does not exist when slide occurs. Such results are used to determine the merits and limitations of DRM and develop design guidelines.
