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- Eriksson, Olle, 1967-, et al.
(författare)
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Statistical analysis of curve squeal based on long-term onboard noise measurements
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Curve squeal with large magnitude tonal components in the frequency range up to 10 kHz is a cause of annoyance without any satisfying solution. This might be partly due to the gaps in the current understanding of the phenomenon within the research community (e.g. the open question whether the fundamental excitation mechanism is due to “falling friction” or “modal coupling”). Rail-bound traffic is expected to become a backbone in the future sustainable public transportation system. This makes it urgent to increase the state of knowledge in order to develop effective mitigation measures against the problem.Noise recorded by an onboard monitoring system during one year of traffic on the Stockholm metro is studied. The influence of selected variables on the generation of curve squeal is investigated in a statistical assessment. The influence of curve radius on curve squeal probability is estimated by calculating the quotient of squealing samples with respect to the total number of samples captured in circular curve sections. Vehicle speed (operative conditions) is modelled by the introduction of a classification representing different speed profiles (e.g. constant, linear acceleration or deacceleration, etc.). Environmental conditions are accounted for by using humidity and air temperature as predictor variables.A general trend of increased probability of curve squeal for decreasing curve radius is observed. Several subsequent regression analyses could not find a consistent influence of air temperature and humidity on the occurrence of curve squeal. Moreover, preliminary results indicate the existence of a vehicle speed for which a curve is particularly prone to generate squeal noise.
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| 2. |
- Eriksson, Olle, 1967-, et al.
(författare)
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Survey of Curve Squeal Occurrence for an Entire Metro System
- 2024
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Ingår i: Noise and Vibration Mitigation for Rail Transportation Systems. - : Springer. - 9789819978519 - 9789819978526 ; 14th International Work-shop on Railway Noise, IWRN 2022, s. 483-490
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Bokkapitel (refereegranskat)abstract
- The current work presents a statistical analysis based on data collected during approximately 1.5 years of regular operation by two vehicles equipped with an on-board noise monitoring system on the Stockholm metro. Data covers 379,776 passages through 143 curves with radii up to 1000 m. Binary logistic regression is used to investigate the importance of curve radius, vehicle speed, relative humidity, air temperature, rail grinding and vehicle individual on curve squeal. Curve squeal occurrence shows an inverse proportionality with respect to curve radius. This trend is particularly pronounced for curve radii below 600 m. The two vehicles accounted for in the study show differences in propensity to generate squeal. The influence of temperature and relative humidity, and their interaction, on curve squeal is described by an estimated response surface. Results show the occurrence of curve squeal to increase after rail grinding. No strong relationship between curve squeal occurrence and vehicle speed is identified.
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| 5. |
- Ögren, Mikael, 1972-, et al.
(författare)
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Nord2000 spår : Beräkning av spårkorrektion från ytråhet på rälen för bullerberäkningar
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I samband med att nya emissionsdata för svenska tåg togs fram för den EU-gemensamma beräkningsmetoden Cnossos-EU och för Nord2000 skapades en korrektion för varje mätplats utifrån den uppmätta ytråheten på rälen. Detta PM beskriver en förenklad metod för att beräkna motsvarande korrektion baserad på den uppmätta ytråheten som sedan går att använda både för beräkningar med den Nordiska metoden reviderad 1996 och med Nord2000.
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