Ultrasonic flexible array for non-destructive testing of complex curved surfaces

Abstract

Ultrasound detection technology in Non-Destructive Testing (NDT) is widely used. Ultrasonic transducer arrays effectively solved the problem of limitation in the detection range of single beam scanning transducers. However, the common used ultrasonic transducer arrays are rigid that are difficult to achieve complete contact with complex curved surfaces. Flexible arrays can be bent to a certain extent and can adaptively fit the surface of different curvature structures for detection. This work reported ultrasonic transducer flexible arrays that combine 2D arrays and linear arrays. The arrays have eight lines and each can be individually controlled. Each line has eight elements. The arrays expand the detection range and greatly reduce the control circuit difficulty and signal processing difficulty. The average operating frequency of the measured arrays is 2.5 MHz, the bandwidth is close to 30% and the insertion loss is close to −33 dB. Also, the arrays can detect defects through curved surface testing. Based on these advantages, this study paved the way for further investigation into the flexible ultrasonic arrays.