| Author: | Liu, Jing |
| Title: | An insight into wave propagation in high-speed train structures and Mass Transit Railway's rails with application to structural health monitoring of railway assets |
| Advisors: | Su, Zhongqing (ME) |
| Degree: | M.Sc. |
| Year: | 2016 |
| Subject: | Railroads -- Maintenance and repair. Elastic wave propagation. Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Mechanical Engineering |
| Pages: | xiii, 146 pages : color illustrations |
| Language: | English |
| Abstract: | The past few decades have witnessed unprecedented development in railway industry, especially for high-speed rail (HSR). With the merits of high capacity, environment respect and high safety, HSR has been wildly used all over the world. The HSR industry in China, started in 2003, has experienced a rapid promotion during last tens of years. However, potential threats behind such a rapid expansion of railway network cannot be ignored: possible failure of train structures during their operation can result in immense life and momentary loss, bringing about irretrievable and disastrous consequences. For high-speed trains (HST), this concern might doubly because of their higher speed, heavier use and also more complex structures, compared with ordinary train vehicles. Nondestructive evaluation (NDE) and structural health monitoring (SHM) techniques have been wildly used to evaluate the integrity and durability of engineering structures and assets. In railway industry, NDE has been employed as a critical tool to maintain and inspect key train structures (such as bogies, rail tracks and axles), in the aim of ensuring operation safety of vehicles. However, NDE has drawbacks such as discontinuity, high labor cost, disruption to normal operations, and the inability to detect damage small in size. Therefore, there is a need to develop an SHM strategy that is able to evaluate the health condition of key train structures in a continuous, real-time, and automated fashion. Both bogie and rail track are key structures to ensure the operation safety of train vehicles. But real-world experiments could also be constrained by limited application capacity and they may become computationally expensive and unsuitable for studying Lamb waves in actual complex engineering structures. Therefore, simulation approaches such as Finite Element Method (FEM) need to be introduced to simulate the propagation of Lamb waves, in order to applicate SHM for train structures and rail tracks. An experiment of SHM for rail track is also conducted to verify the feasibility of SHM systems. All the simulations of Lamb waves are completed in ABAQUS®/Explicit. In the FE simulation, the propagation behaviors of Lamb wave in the bogie frame and the rail track have been investigated. Based on simulation results, with the help of a novel signal processing tool to extract both temporal and spectral information from Lamb wave signals, damages are able to be localized using the linear feature of signal waves. Conclusively, localizations of damages on the side-panel of bogie frame and on the surface of rail track are accomplished, indicating the effectiveness of recommended simulation approach in evaluating presence and location of such damage in train structures and rail tracks. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b2910922x.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 6.06 MB | Adobe PDF | View/Open |
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