Practical applications of active mass dampers with hydraulic actuator

The application of active mass damper (AMD) systems into buildings has been studied analytically and experimentally during the 1980s. The main purpose of these systems is to reduce the vibrations of buildings during strong wi nds or small earthquakes in order to improve the comfort of the building oc cupants. The authors have worked on the study and development of an AMD sys tem using an electro-servo-type hydraulic actuator. First, the control technique of AMD with hydraulic actuator is formulated. Hydraulic actuators have an advantage of high durability and high cost perf ormance, however, they also have non-linear dynamics, which makes their con trol difficult. Second, the applications of this system in the buildings are shown. The aut hors have applied this AMD system to four buildings in Japan. The outlines of these AMDs and buildings are described individually. To verify the contr ol performance of the AMD in these buildings, free vibration tests were car ried out just before their completion. Free vibration test results of each building demonstrated good control performance. After the completion, wind and earthquake observations were conducted. The records have shown a good p erformance of energy absorption of the vibration during wind excitation and small level earthquakes. Copyright (C) 2001 John Wiley & Sons, Ltd.