Crack defects in metallic materials severely compromise structural integrity, and the ultrasonic detection and characterization of vertical cracks remain challenging due to wave scattering, attenuation, and limited penetration. This paper proposes a correction-enhanced frequency-domain reverse-time migration (CF-RTM) method for ultrasonic imaging of vertical cracks. The method introduces a correction-enhanced factor to mitigate the influence of ultrasonic wave diffusion and attenuation in the vertical crack defect region. It then applies frequency-domain RTM for crack defect image reconstruction, which reduces computational complexity and enhances image quality. Experimental results demonstrate that CF-RTM effectively balances the amplitude distribution between the shallow and deep regions of defects, thereby enhancing the detectability of deep vertical cracks. Compared with the total focusing method (TFM), CF-RTM demonstrates significant advantages in identifying the deep regions of cracks and overall defect morphology reconstruction, providing more uniform amplitude distribution and a more complete defect morphology. In lateral amplitude comparison, the proposed method achieves a peak value 57.31% higher than TFM, confirming the method’s capability in imaging deep crack defects.
Chen et al. (Mon,) studied this question.