@article{e2ee876344c749cdb57f7e6661a9944e,
title = "On the existence of zero-group velocity modes in free rails: Modeling and experiments",
abstract = "Zero-group velocity (ZGV) modes in rails are studied through simulation and experiments in this work. Local resonances associated with ZGV modes appear as distinct, sharp peaks in the frequency amplitude spectrum, whose resonant frequencies can serve as indicators of the local structural integrity condition of the rail itself, assuming that one can excite, detect, and identify wave mode type with confidence. To better understand these interesting modes, semi-analytical finite element (SAFE) analysis is implemented to compute dispersion curves of a standard rail and to identify potential ZGV points. A fully discretized Finite Element (FDFE) model then simulates responses of a free rail when subjected to impulse-based dynamic testing. Experimental impulse vibration data are collected from a 25-m rail with multiple impact-receiver configurations to understand the detectability and excitability of specific resonances associated with ZGV modes in rails. Spatial sampling of wave disturbance is performed to calculate the dispersion relations experimentally via two-dimensional Fourier Transforms (2D-FFT). The excellent agreement between simulation and experimental results confirms the existence of ZGV modes and cutoff frequency resonances in rails and verifies the feasibility of using impulse-based dynamic tests for the promotion of ZGV modes.",
keywords = "Guided waves, NDE, Numerical simulation, Rail transportation, Zero-group velocity modes",
author = "Yuning Wu and Ranting Cui and Keping Zhang and Xuan Zhu and Popovics, {John S.}",
note = "Funding Information: This work was supported by the U.S. National Academy of Sciences Rail Safety IDEA program, project RS-41. The authors acknowledge and appreciate the input from IDEA program manager Dr. Basemera-Fitzpatrick and the expert review panel associated with the project. The opinion expressed in this paper are solely of the authors, and the U.S. National Academy of Sciences, Engineering, and Medicine and the U.S. Government do not necessarily concur with, endorse, or adopt the findings, conclusions, and recommendations either inferred or expressly stated in the paper. This work was also partially funded by the startup package at the University of Utah . The support and resources from the Center for High Performance Computing at the University of Utah are gratefully acknowledged. The field data collection was coordinated and supported by the Utah Transit Authority. Funding Information: This work was supported by the U.S. National Academy of Sciences Rail Safety IDEA program, project RS-41. The authors acknowledge and appreciate the input from IDEA program manager Dr. Basemera-Fitzpatrick and the expert review panel associated with the project. The opinion expressed in this paper are solely of the authors, and the U.S. National Academy of Sciences, Engineering, and Medicine and the U.S. Government do not necessarily concur with, endorse, or adopt the findings, conclusions, and recommendations either inferred or expressly stated in the paper. This work was also partially funded by the startup package at the University of Utah. The support and resources from the Center for High Performance Computing at the University of Utah are gratefully acknowledged. The field data collection was coordinated and supported by the Utah Transit Authority. Publisher Copyright: {\textcopyright} 2022 Elsevier Ltd",
year = "2022",
month = dec,
doi = "10.1016/j.ndteint.2022.102727",
language = "English (US)",
volume = "132",
journal = "NDT International",
issn = "0963-8695",
publisher = "Elsevier Limited",
}