Correction method with stress field effects in ultrasound nondestructive testing

Ultrasound detection is widely applied to evaluate the quality of mechanical parts. However, a detection error is caused by the structural stress that influences the propagating parameters of ultrasound. In this paper, after discussing the quantitative effects of the stress field, a correction method for ultrasound detection is presented based on ultrasound propagation and acoustoelastic theory. The quantitative relationship between the velocity of ultrasound and stress field is analysed, and a theoretical function to calculate the difference between the measured and actual propagation distance is established. Then, ultrasound testing is designed with variable stress type (compressive and tensile) and direction of ultrasound (parallel and vertical), and the experimental results are compared to verify this proposed theoretical function. Considering the variable requirements and conditions of ultrasound detection in industry, the correction method with stress factor is proposed to improve the credibility of the measured results in ultrasound detection.