Damage detection method based on operating deflection shape curvature extracted from dynamic response of a passing vehicle

This paper describes the development of a local damage detection method for beam and plate like structures based on operating deflection shape curvature extracted from dynamic response of a passing vehicle, which serves both as “exciter” and “message carrier”. Based on the operating deflection shape curvature and the assumption that the intact structure is smooth and homogenous, a new damage detection algorithm called Global Filtering Method (GFM) is proposed. The new method using only information from damaged structures has been verified by both numerical simulations and experiments. Even if only using operating deflection shape curvatures at relatively few frequencies near the first natural frequency, not only local damage in beam could be detected in the numerical simulation, delamination as small as 8 mm in composite plate could also be detected in the laboratory. Compared with traditional methods using operating deflection shape data extracted from FRFs; it is time-saving, easier to implement and produces greater accuracy as it does not require many preinstalled sensors and solving eigenvector or singular value problems.

► The operating deflection shape is defined and extracted by the interaction of vehicle and beam or plate like structures.
► The pre-filtering by wavelet is used to calculate more accurate and smooth curvature of operating deflection shape.
► The Global Filtering method is proposed for detecting local damages without “baseline”.
► Only operating deflection shape near the first natural frequency is required.