Bridge Damage Detection from Contact Response of a Scanning Vehicle by a Novel Entropy Method

A novel entropy method for detecting bridge damages from the vehicle-bridge contact response of a scanning vehicle is proposed, with no baseline or reference required. First, the closed-form solution for the vehicle-bridge contact point is derived, along with a formula for back-calculating the contact response from the vehicle response. Then, the hierarchical multi-scale time–frequency permutation entropy (HMTFPE) is used to extract complex fault messages from both the low- and high-frequency components in the time–frequency domain. Further, a sliding time-window (STW) is included for the first time to detect the damage locations from the contact response, to form the so-called STW-HMTFPE method. Subsequently, the efficacy of the proposed technique was numerically validated. Based on the parametric studies, it was demonstrated that the proposed STW-HMTFPE method: (1) can be effectively used to detect the location of bridge damages, (2) is robust against various factors considered, (3) can identify not only single- but also multi-damage scenarios, and (4) is effective in face of pavement roughness when aided by an accompanying truck in the scanning process.