Indirect Damage detection in bridge using transmissibility measurements from the response of a passing vehicle

In most of the bridge health monitoring techniques based on vibration, a large number of sensors are installed on the structure which may be costly and time-consuming. Recently, some methods have been proposed in which the response of a passing vehicle is utilized in order to achieve the modal properties of the bridge. In this paper, transmissibility measurement of the vehicle response is dedicated to detect the bridge damage indirectly. Since the data is transmitted by accelerometers embedded on the axles of the vehicle, the vehicle is passing over the bridge without stopping and accelerometer is recording without interruption. As another advantage of the method is that the white noise assumption in not necessary for the excitation signal unlike the other related methods. Here, the bridge is modeled by finite element and vehicle is assumed to be two 2DOF systems of mass-spring-damper. By solving the vehicle-bridge interaction equations, the vehicle response is obtained in order to estimate the intact mode shape. Afterwards, a damage is considered in the brdige and the change in mode shape curvature are used for damage localization. Numerical investigations reveal that the proposed method can localize the damage by acceptable accuracy in the presence of noise.