System identification for damage detection in buildings

An algorithm for damage detection in a multi-story building modeled by a wave equation with Kelvin damping is presented. Damage detection is achieved by relating stiffness loss with reduction in the shear wave velocity of the seismic induced motion propagation through the structure. In order to estimate wave velocity and damping parameters, an identification system based on the least squares method with forgetting factor is used. In addition, a parameterization is presented based on linear integral filters, which eliminates constant disturbances, attenuate measurement noise and depend only on acceleration signals. Once parameters information is available, a detection threshold is designed that compares them with reference values. The experimental results validate the feasibility of the proposed method.