SN-FSAT system for single sensor ultrasonic guided wave beam steering and damage detection

In wireless communications as well as in structural health monitoring (SHM) beam steering presents interesting advantages. In the former it plays an important role for data directivity, which is also a perk for energy efficiency and data security; for the latter, directional inspection through guided waves (GW) leads also to energy efficiency, arbitrary dedicated space scanning, multi-function operation through multiple beams and even to application of a base-line free inspection concept. Normally, to enable this simultaneous beam control and data communication in arbitrary spatial directions (2D) over a structure, a large array of transducers is required, arranged to a similarly complex hardware and software support system. In this work, we present a system based on a dedicated sensor node (SN) and frequency steerable acoustic transducer (FSAT) combination. The SN-FSAT system is responsible for appropriate power and signal management for acquisition, transmission, processing, and evaluation of data required for spatial sensing and damage detection as well as directional focused wireless communication. These were tested over an isotropic aluminum plate-like structure by means of a double symmetric beam, via differential actuation signals, or in a high directive beam in a single direction by means of a quadrature driving signals. The complete guided wave-based setup consists of a SN-FSAT pair glued to an aluminium plate, a small metallic dick mass attached to the plate surface with damping tacky tape to simulate damage. The results show that damage located in different positions around the FSATs can be detected. © 2024, NDT. net GmbH and Co. KG. All rights reserved.