Cracks detection of beam-type structures based on curvature in time domain using smeared crack model

A new damage index named smeared cracked model damage index (SCMDI) based on the mean curvature of beam-type structure in time domain to detect cracks is presented, which introduces the smeared cracked model in damage mechanics, is demonstrated to be more robust and high efficiency in crack detection using a numerical model. The discrete measured responses for specified time interval are used to obtain the curvature of each section corresponding to nodes of the finite element model of continuous beam, and the mean curvature of each section in time domain is used to build a damage index that represents the relative ratio of the loss of curvature of the pre-damaged to the post-damaged beam. The SCMDI is used to identify possible locations and corresponding severities of cracks in the beam-type structure. The numerical simulation of a continuous beam demonstrates the validity of the proposed SCMDI.