Using an Instrumented Tractor-Trailer to Detect Damage in Bridges

This paper investigates an alternative to Structural Health Monitoring (SHM) which involves no sensors on the bridge itself. It uses a vehicle fitted with accelerometers on its axles as a method of monitoring the dynamic behavior of the bridge, which in turn gives an indication of the bridge's structural condition. The concept, known as 'drive by' bridge inspection, may be of particular value after an extreme event, such as an earthquake or a flood, where a rapid indication of bridge condition is needed. In the paper, a two dimensional numerical model is described of a 3-axle truck towing a half-car trailer. The vehicle-bridge dynamic interaction is modeled to test the effectiveness of the approach in identifying the structural damping of the bridge. The damping of the bridge is used here as an indicator of damage. The accelerations in the two axles of the trailer are subtracted to remove the effect of the road profile. Results indicate that the algorithm works well and is not sensitive to transverse position of the vehicle on the bridge.