Dynamic Parameter Identification of Secondary Mass Dampers Based on Full-Scale Tests

For a secondary mass damper such as tuned liquid damper (TLD) or tuned liquid column damper (TLCD), whose moving mass is liquid, it is impossible to prefabricate the damper in a factory for the identification of dynamic properties. Also, it is not easy to prefabricate a concrete tuned mass damper (TMD), whose moving mass is made of concrete, in a factory. In this article, an identification method for finding dynamic properties of secondary mass dampers based on the full-scale field test is presented. Decoupled equations of motion are derived from a coupled equation of motion of building and damper. The decoupled equations of motion are then used for system identification using the response of the damper as an input and the response of the building as an output. The proposed method is applied to numerical examples and an actual TMD and TLCD installed in buildings.