Automated Data Fusion and Visualization for Impact-Echo Testing of Concrete Structures

An automated data fusion and visualization process is developed for nondestructive evaluation and direct visualization of internal defects of concrete structures based on impact-echo testing using source-receiver arrays. In the process, the ratio between the amplitudes of major echo peaks in the frequency spectrum (after noise reduction) and the bottom echo signal is proposed as a feature parameter for data fusion. The fused results then go through image segmentation, which combines thresholding and region growing to extract defect regions for visualization. The effectiveness of the automated data fusion and visualization process is validated using both numerical simulation and experimental testing.