Operational conditions monitoring of SHM systems applied to guided wave imaging

作者：Maël Pénicaud, A. Recoquillay, C. Fisher, A. Imperiale · 发表于：e-Journal of Nondestructive Testing · 年份：2026 · DOI：10.58286/34076

Guided Waves are commonly used for measurements of thickness loss, presence and gravity of defects in structures such as oil&gas pipes or aeronautical structures due to their capacity to propagate over long distances and their sensibility to materials variations. Common imaging techniques include Delay-And-Sum (DAS), RAPID or Minimum Variance imaging [1][2]. These methods require a baseline to compare the current state of the structure with a previous measured state. Specifically, these techniques may be altered through varying environmental and operational conditions (EOCs) between multiple measurements. Varying EOCs may include aging of the coupling between the sensor and the structure, changes in temperature, humidity, or external loadings of the structure. As the influence of these factors may be comparable to the influence of defects in the structure on the propagating guided waves, they have to be accounted for. While some methods exist to compensate the variations such as Baseline Signal Stretch (BSS) or Optimal Baseline Selection (OBS)[3], they are either insufficient for a full range of varying conditions or very costly in required experiments, and may not be suited for industrial applications with complex environments [4]. More generally, these techniques require precise knowledge about the propagation of guided waves, for example the group velocity to locate a defect in DAS. To address these problematics, we present an optimization process aiming at retrieving effe...