Rail dampers typically provide 3–4 dB(A) noise reduction, but occasionally 5–10 dB(A) for lightly damped rails on soft fasteners (Ho et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 89–96, 2012; Thompson et al. in Appl Acoust 68:43–57, 2007; Lo et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 638–645, 2019; Ho et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 654–661, 2019; Ho et al. in Noise reduction effect by rail damper on single rail, 2021 [1–5]). For retrofit applications, rail dampers often perform below their capacities due to poor connection at the rubber/metal interface due to uncontrollable rusted surface and rail profile tolerance. The rubber/metal interface is soft to maximize the contact area, but is not so soft that it becomes an isolator rather than a vibration absorber. Rigid Contact TMD (RCTMD) rail damper uses metal-to-metal mounting plates (Ho et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 89–96, 2012; Lo et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 638–645, 2019; Ho et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 654–661, 2019; Ho et al. in Noise reduction effect by rail damper on single rail, 2021; Ho et al. in Tuned mass damper design optimization using FEA, 2014; Tam et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 585–593, 2016; Ho et al. in Tuned mass damper for rail noise and corrugation control. Proceeding of acoustics, 2012; Ho and Wong in Tuned mass damper for rail noise and corrugation control. Proceeding of the 5th cross-strait acoustical conferences, 2012; Ho et al. in Reducing rail corrugation growth by tuned mass damper, 2013; Ho et al. in Analytical study on railway corrugation growth control by tuned mass damper, 2014; Ho et al. in Suppression of corrugation growth by rail damper, 2021; Ho et al. in Groundborne noise reduction by rail damper effect on P2 resonance 2021; Ho et al. in TMD tunable for railway groundborne noise control, 2021 [1, 3–14]) that repositions the rubber/metal interface into a flat surface aligned perpendicular to the rails for tolerance control. Multiple RCTMDs increase the rubber/metal interface area. With multi-frequency tunable TMD customized for individual rails at curve, it reduces corrugation growth rate by 50–90% (Ho et al. in Noise and vibration mitigation for rail transportation systems. Springer, pp 89–96, 2012; Ho et al. in Noise reduction effect by rail damper on single rail, 2021; Ho et al. in Proceeding of acoustics, 2012; Ho and Wong, Proceeding of the 5th cross-strait acoustical conferences, 2012; Ho et al. in Reducing rail corrugation growth by tuned mass damper, 2013; Ho et al. in Analytical study on railway corrugation growth control by tuned mass damper, 2014; Ho et al. in Suppression of corrugation growth by rail damper, 2021 [1, 5, 8–12]), and all curve track corrugations are suppressed. Single-frequency RCTMD (550 Hz, lateral pin-pin resonance) achieved the – 4 dB(A) project requirement with 1 RCTMD per space on low rail, where RCTMD is short-length design for fitting 2 RCTMDs per space for contingency (Ho et al. in Noise reduction effect by rail damper on single rail, 2021 [5]). When RCTMD is tuned to rail P2 resonance (47 Hz), the concrete floor vibration level is reduced by 6–8 dB(A) (Ho et al. in Groundborne noise reduction by rail damper effect on P2 resonance 2021; Ho et al. in TMD tunable for railway groundborne noise control, 2021 [13, 14]) under a laboratory setting with a 6.3 m rail sitting on resilient fasteners (~17 kN/mm) with a ~ 450 kg steel block to simulate the weight of a half wheelset on rail. It is a potential retrofit measure to mitigate railway groundborne noise caused P2 resonance. Around the world, train speed restrictions are occasionally adopted to reduce noise. Such speed restrictions will be unnecessary when reliable dampers performances are shown to the railway operators.
Strong Rail Damper Development
Lect.Notes Mechanical Engineering
International Workshop on Railway Noise ; 2022 ; Shanghai, China December 07, 2022 - December 09, 2022
Noise and Vibration Mitigation for Rail Transportation Systems ; Kapitel : 39 ; 417-427
2024-02-24
11 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
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