Investigating the Contact-Point Response for Drive-By Damage Detection in Bridges

Bridges are critical elements in any road or rail transport network and ensuring their safety is paramount. Recent years have seen significant research efforts to develop cost-effective techniques for bridge monitoring on a large scale. Drive-by bridge inspection techniques, whereby sensors inside a vehicle are used to monitor bridge condition, are at the focus of much of this work. This paper develops a relationship between the measured response in a vehicle and the contact-point response between the wheel and the surface of a bridge using a quarter-car representation of the vehicle. Numerical simulations are carried out to examine the feasibility of using the contact-point response as an indicator of damage. A number of passages of the quarter-car vehicle model traversing a Finite Element representation of a bridge are simulated and the contact-point response is evaluated for each passage. Varying levels of damage are simulated in the bridge to assess whether the presence of damage can be detected by the contact-point response. Results show that the method is very effective at identifying the bridge frequencies and can also detect changes in bridge frequency with increasing damage levels. A major advantage of using the contact-point response as a damage indicator lies in its ability to detect bridge frequencies without being influenced by the vibrational frequencies of the vehicle itself. The contact-point response shows promise for implementation into drive-by bridge inspection regimes, however further work is required to investigate the feasibility of the approach at higher vehicle speeds.