Comparative evaluation of in situ stress monitoring with Rayleigh waves
Autor: | James M. Hughes, L. R. F. Rose, Aditya Khanna, Ching-Tai Ng, A. Kotooussov, James Vidler, Munawwar Mohabuth |
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Rok vydání: | 2018 |
Předmět: |
Physics
Rose (mathematics) Mechanical Engineering Acoustics Biophysics 020101 civil engineering 02 engineering and technology Stress monitoring In situ stress 01 natural sciences ADITYA 0201 civil engineering Comparative evaluation symbols.namesake 0103 physical sciences Acoustoelastic effect symbols Rayleigh wave 010301 acoustics |
Zdroj: | Structural Health Monitoring. 18:205-215 |
ISSN: | 1741-3168 1475-9217 |
Popis: | The in situ monitoring of stresses provides a crucial input for residual life prognosis and is an integral part of structural health monitoring systems. Stress monitoring is generally achieved by utilising the acoustoelastic effect, which relates the speed of elastic waves in a solid, typically longitudinal and shear waves, to the stress state. A major shortcoming of methods based on the acoustoelastic effect is their poor sensitivity. Another shortcoming of acoustoelastic methods is associated with the rapid attenuation of bulk waves in the propagation medium, requiring the use of dense sensor networks. The purpose of this article is twofold: to demonstrate the application of Rayleigh (guided) waves rather than bulk waves towards stress monitoring based on acoustoelasticity, and to propose a new method for stress monitoring based on the rate of accumulation of the second harmonic of large-amplitude Rayleigh waves. An experimental study is conducted using the cross-correlation signal processing technique to increase the accuracy of determining Rayleigh wave speeds when compared with traditional methods. This demonstrates the feasibility of Rayleigh wave–based acoustoelastic structural health monitoring systems, which could easily be integrated with existing sensor networks. Second harmonic generation is then investigated to demonstrate the sensitivity of higher order harmonics to stress-induced nonlinearities. The outcomes of this study demonstrate that the sensitivity of the new second harmonic generation method is several orders of magnitude greater than the acoustoelastic method, making the proposed method more suitable for development for online stress monitoring of in-service structures. |
Databáze: | OpenAIRE |
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