Damage Identification of Reinforced Concrete Beams Based on Digital Image Correlation Technology

To study the damage identification of reinforced concrete beams based on the digital image correlation (DIC) technology, four groups of reinforced concrete beams with different shear span ratios were designed, and the speckle patterns were artificially painted on the surface of the beams;The vertical displacement of the whole span of the beams was measured by DIC technology, and meanwhile the vertical displacement at the mid-span of beams was obtained by the traditional displacement meter and laser displacement meter.The damage identification equation of the bending stiffness distribution was established for RC beams subject to loads, by the utilization of the Green's function, the first kind of Fredholm integral and the mathematical algorithm of regularized numerical solution.According to the load-displacement curve of the test beams measured by DIC technology, the stiffness damage of the concrete beams under different loads was identified.The research results show that:the measurement of DIC technology is basically consistent with the displacement curve obtained by the traditional displacement measurement, and the error is acceptable;the damage identification equation developed herein can permit an accurate identification of the stiffness for the beams.