Passive control of structures: experimental verification using tuned mass dampers

摘要

The focus of this thesis is to review and experimentally verify the effect of vibrationaludcontrol systems applied in tall and flexible structures. The installation of these systems onudnew and existing structures aim at the spectacular improvement of the structural dynamicudbehavior under different types of manmade and ambient excitations on the concepts ofudstructural safety and operational conditions.udThe control theory of this thesis is applied for the design of Passive Control Systems andudmore specifically for the design of Tuned Mass Damper (TMD) installed properly on theudmain structure. The main mass of the Tuned Mass Damper, which is named as secondaryudsystem, is significantly smaller than the main mass of the primary system which is audSingle Degree of Freedom (SDOF) system.udA series of experiments with one and two TMDs installed on a SDOF modeled smalludlaboratory structure are designed, constructed and performed. The structural behavior ofudthe laboratory structure was tested by subjecting to artificially induced harmonicudexcitation and one of the components available during the strong El Centro earthquake.udThe main modal characteristics of the combined primary-secondary system studied areudthe modal frequencies, the damping coefficients and the mass ratios between primary andudsecondary systems.udA smart laboratory technique for damping improvement of structures was also employedudto both primary and secondary systems and it is shown that sensibly contributes toudvibration attenuation of the primary system.udAll the experimental concepts and results are discussed herein and demonstrate theudeffectiveness and reliability of Passive Control Systems installed on tall and flexibleudstructures that are susceptible to strong winds and earthquake events.