Three-stage Lamb-wave-based damage localization algorithm in plate-like structures for structural health monitoring applications

In this paper, a new two-dimensional localization algorithm based on the combination of detection theory and array processing frameworks is presented. Our proposed method is capable to extract locations of multi-damage in a plate-like structure for structural health monitoring purpose. The proposed technique is a three-stage localization algorithm. In the first stage, a signal activity detection (SAD) algorithm is applied to extract curved delays of interested damages, which are in the near-field of the array. Then, a new high-resolution technique, named compensated curved-time delay version of amplitude and phase estimation (CTD-APES), is proposed to estimate damage direction of arrivals. Finally, at the third stage of our proposed algorithm, the location of detected damages are found based on the obtained results of the SAD and CTD-APES algorithms. Unlike most existing works, the proposed method is developed based on the spatial-wideband effect as well as near-field nature across the receiving antenna array; thus the proposed method along with the problem formulation can be considered as a new analytical framework in this topic. Extensive Monte Carlo simulation results are provided to demonstrate the superiority of the proposed technique as well as to validate the theoretical calculations. (C) 2019 Elsevier B.V. All rights reserved.