High-precision ultrasonic imaging method for internal defect of complex-shaped component based on search-vector imaging condition

Abstract

The present disclosure provides a high-precision ultrasonic imaging method for an internal defect of a complex-shaped component based on a search-vector imaging condition. Based on full waveform inversion, the search-vector imaging condition is constructed, and a first-order derivative vector is combined with an approximate Hessian matrix for correction so that a high-quality image of a defect in a complex sound velocity model can be obtained. The high-precision ultrasonic imaging method is suitable for defect testing on complex surface components. The imaging condition used for the imaging method of the present disclosure does not involve an assumption on a wave field and is stricter than a traditional imaging condition theory, thereby ensuring high precision of the inventive method. Moreover, the imaging method of the present disclosure can highlight a defect in an entire measurement area, which is very convenient for locating a defect in a large-size measurement structure.