If a building structure requires both a vibration control system and a health monitoring system,the integration of the two systems will be cost-effective and beneficial for creating a smart structure. One of the key problems of this integrated system is how to use control devices to enhance system identification and damage detection. This paper presents a new method for system identification and damage detection of building structures through model updating based on semi-active friction dampers and frequency response functions of the building structure. By adding a known stiffness using semi-active friction dampers,the two states of the building can be created: the building without any additional stiffness; and the building with additional stiffness. A scheme based on the frequency response functions of the two states of the building is first presented to update the stiffness matrix and to identify stiffness parameters of structural members in consideration of structural connectivity and transformation information. By assuming that the building suffers certain damage after extreme events or long service and by applying the proposed model updating scheme to the damaged building,a damage detection scheme is then proposed based on the identified stiffness parameters of structural members of both the original and damaged buildings. The feasibility of the proposed schemes is finally demonstrated through a detailed numerical investigation in terms of an example building,in which the effects of measurement noise and excitation conditions are discussed. The numerical results clearly show that the proposed method can locate and quantify damage satisfactorily even though measurement noise is taken into consideration.
Building structures Damage detection Frequency response function Semi-active friction damper Measurement noise
Q. Huang Y.L.Xu J.C. Li H.J. Liu Z.Q. Su
Shenzhen Graduate School,Harbin Institute of Technology,Shenzhen 518055,P.R. China Department of Civ Department of Civil and Structural Engineering,The Hong Kong Polytechnic University,Kowloon,Hong Kon School of Civil and Environmental Engineering,University of Technology Sydney,Sydney,Australia Shenzhen Graduate School,Harbin Institute of Technology,Shenzhen 518055,P.R. China Department of Mechanical Engineering,The Hong Kong Polytechnic University,Kowloon,Hong Kong