Nondestructive crack detection algorithm for full-scale bridges

A nondestructive crack detection (NCD) scheme to locate a crack and estimate the crack size by using changes in the modal parameters of a class of bridges is presented in this paper. First, the theory underlying a nondestructive crack localization and crack-size estimation algorithm for beam-type structures is outlined. Next, a field experiment to verify the feasibility and applicability of the NCD scheme is detailed. In that experiment, predamage and postdamage modal data extracted from a full-scale plate-girder bridge are described. The modal data are fed into the NCD scheme that localizes crack and estimates crack size in the test structure. The result of the analysis indicates that the proposed NCD algorithm correctly locates the crack and accurately estimates the size of the crack.