Guided wave enhancement phased array beamforming scheme using recursive feedback

Guided waves are well established and beneficial tools of ultrasonic nondestructive evaluation applications. Using a phased array it is possible to ensure selectivity, both in terms of the mode and the direction of the wave. Yet, there is a growing need to improve both selectivity and power efficiency of the transmitted ultrasonic wave. The aim of this study is to improve the identification of cracks in thin plates and pipes. In this work, a novel adaptive beamforming technique for guided waves is developed. The method is based on a recursive feedback algorithm which optimizes the individual excitation waveforms to increase the total energy at a desired mode, and enhance a unidirectional propagation of the ultrasonic wave.