8th ASCE Specialty Conference on Probabilistic Mechanics and Structural Reliability PMC2000-305 Kim and Stubbs 1 NONDESTRUCTIVE CRACK DETECTION MODEL AND VIBRATION- BASED SYSTEM IDENTIFICATION IN STRUCTURES

A methodology to nondestructively locate a crack and estimate the crack-size by using changes in the dynamic modal parameters of a class of bridges is presented. First, a theory of nondestructive crack localization and crack-size estimation algorithm that related to beam-type structures is outlined. Next, an experiment to verify the practicality of the nondestructive crack detection (NCD) scheme is performed. Pre-damage and post-damage dynamic 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. Results of the analysis indicate that the NCD scheme correctly localize the crack and closely estimates the crack-size