Theoretical calculation on distance amplitude curve of ultrasonic phased array

Ultrasonic phased array technology has been gradually applied to industrial nondestructive testing in recent years.The sound field of the focusing and steering beam radiating from the phased array is a nonuniform distribution in the spatial position so that the echo signals of same size defects will be changed according to defect positions.To analyze these defects quantitatively,a model-based method for the distance amplitude correction is proposed for the phased array system.Based on a non-paraxial multi-Gaussian beam model and flaw scattering models,an ultrasonic measurement model for the phased array system is proposed to calculate the echo signals from side-drilled holes at different positions.Furthermore,these model-based distance amplitude curves are compared with the traditional experimental results for different focusing and steering beams.The two methods have a good agreement.