TMD Control Of Structural Response Under Wind And Earthquake

The concept of structural control was first proposed by J. P. Yao (1972). Since then, numerous control devices have been developed for enhancing structural functionality and safety against natural and manmade hazards. Among various vibration control devices, tuned mass damper (TMD) is one of most popular and suitable control devices for buildings and other structures. Based on the studies at home and abroad, more experimental and theoretical studies for TMD control of structures under wind and earthquake are carried out here and summarized as follows:(1)TMDs are known to be very effective in controlling vibrations caused by a stationary disturbance, such as wind loads. The suspended TMD has been designed for wind control of Henan Art Center symbolic tower in Zhengzhou, China. Performance test of designed TMD is carried out and linear and nonlinear analysis of TMD control effective is performed using SAP2000. The designed pendulum TMD is adjusted and installed on the spot. The designed TMD adopted universal joint linking primary structures and rigidity steeve, making it works in all directions and avoiding torsion and twittering of mass. The designed TMD adopted frictional flake to supply damping, making it less expensive and reliable. Performance test in laboratory presented the designed TMD can meet the required demand within a certain parameters adjusting range. Nonlinear analysis indicates that for certain loads the optimal friction can achieve good control effective in large range of loads.(2)Because of the complexity of earthquake, there has not consistent conclusion about the control effectiveness of TMD for earthquake response of structures. The different methods for TMD parameter optimization are compared and their seismic control effectiveness is compared. Based on the concept of response spectra, the seismic response control effectiveness of TMD for SDOF system is studied. And the results indicate that TMD is effective for SDOF structure subjected to earthquake ground motion. Based on Henan Art Center Symbolic Tower, the earthquake control of TMD and MTMD are studied.(3) The theoretical and experimental study on normal friction TMD with constant friction coefficient are carried out and the results indicated that under harmonic loads friction TMD with large friction force can reduce the peak value of frequency response curve, and the range of non-work is increase with the friction force increase. Wind and earthquake control analysis indicate that for different structures under different magnitude of excitation, the control effect of friction TMD with constant friction force is different.(4) To enhance the control effectiveness of friction TMD with constant friction force, the variable friction TMD is presented and the theoretical and experimental study are carried out. The results demonstrate that the control effectiveness of variable friction TMD is not change remarkably with the change of magnitude of excitation.(5)Earthquake is typical non-stationary dynamic loads and usually achieves peak value in short time, while passive TMD need some time interval to grow required displacement for reaching their full operational state. Thus, when a peak acceleration in a earthquake ground motion comes so early the control effectiveness of TMDs is limited due to their slow start-up. A new type of velocity adjustable semi-active TMD is presented, which can accelerate TMD and adjust phase relationship between primary structure and TMD. According to the working mechanism of TMD, rules of adjusting velocity are established. The analysis program is developed in VB platform. Seismic response of SDOF structures with passive TMD and velocity adjustable TMD are analyzed. The control effectiveness of MTMD, AMD and velocity adjustable TMD are compared. The results demonstrate that velocity adjustable TMD has remarkable advantage in earthquake control.