Drive-by damage detection with a TSD and time-shifted curvature

‘Drive-by’ damage detection is the concept of using sensors on a passing vehicle to detect damage in a bridge. The newly developed traffic speed deflectometer (TSD) is a device used for pavement velocity/deflection measurements and is investigated here in numerical simulations as a means of bridge damage detection. A TSD vehicle model containing five displacement sensors is simulated crossing a simply supported finite element beam containing damage simulated as a loss in stiffness of one of the elements. Time-shifted curvature is derived from the displacements and is proposed as a novel damage indicator, which removes the influence of the road profile and all vehicle motions except for pitch. Results show that the time-shifted curvature can be reliably used as a damage indicator in the presence of noise and changes in transverse position of the vehicle on the bridge.