Indirect structural health monitoring of bridge structures using moving sensors

Bridge infrastructure is subject to continuous degradation due to the ageing, environmental and excess loading. Monitoring of these structures is a key part of any maintenance strategy as it can give early warning if a bridge is becoming unsafe. A novel approach is proposed to identify the local damages of a bridge deck using a moving vehicle which acts as a moving sensor. The dynamic response of the vehicle is monitored using accelerometers located on both the axle and vehicle body when crossing the bridge deck. The interaction force between the vehicle and the bridge are obtained from the measured responses. Local damages of the deck are identified by minimizing the error between the calculated and measured interaction force through adaptive regularization techniques. Simulation results show that the interaction force is much more sensitive to the local damages of the structure than the acceleration responses of the vehicle or the bridge. Effects of parameters of the moving vehicle with different road surface roughness are studied. The effect of measurement noise in single and multiple damage identification is also discussed. The identified results are found less sensitive to the measurement noise with a slower or heavier vehicle.