Porovnání různých zátěžných spekter na zbytkovou únavovou životnost železničních náprav

Comparison of Different Load Spectra on Residual Fatigue Lifetime of Railway Axle

článek v časopise ve Web of Science, Jimp

en

The railway axles are subjected to variable amplitude loading. The variability is caused by many different regimes of train operation. The dominant load is caused by the weight of the vehicle, which generates rotary bending during train movement. Nevertheless, there are additional forces, which are generated when train goes through curved track, over crossovers, switches, rail joints etc. Present non-destructive defectoscopy can reliably detect only relatively long cracks (approximately 2 mm long or longer). Hence there is a risk that the existing crack is not detected. Therefore, for conservative estimation of the residual fatigue lifetime the railway axle with a crack should be considered. The behaviour of the crack depends on load spectrum of railway axle. Hence for accurate determination of residual fatigue lifetime of the railway axle is necessary to know representative load spectrum. This paper compares several measured load spectra of railway axles, which are available in the literature. The effect of different load spectra is shown on two widely used materials for railway axles: EA1N and EA4T steels. Obtained results could be used for safer operation of railway axles.

Železniční nápravy jsou v průběhu provozu vystaveny proměnnému zatěžování. Toto zatížení je dáno především typem tratě, dvojkolí či způsobem provozování. Tento článek zkoumá vliv několika dostupných zátěžných spekter železničních náprav na zbytkovou únavovou životnost železničních náprav, u kterých je předpokládaný počáteční defekt typu trhlina.

The railway axles are subjected to variable amplitude loading. The variability is caused by many different regimes of train operation. The dominant load is caused by the weight of the vehicle, which generates rotary bending during train movement. Nevertheless, there are additional forces, which are generated when train goes through curved track, over crossovers, switches, rail joints etc. Present non-destructive defectoscopy can reliably detect only relatively long cracks (approximately 2 mm long or longer). Hence there is a risk that the existing crack is not detected. Therefore, for conservative estimation of the residual fatigue lifetime the railway axle with a crack should be considered. The behaviour of the crack depends on load spectrum of railway axle. Hence for accurate determination of residual fatigue lifetime of the railway axle is necessary to know representative load spectrum. This paper compares several measured load spectra of railway axles, which are available in the literature. The effect of different load spectra is shown on two widely used materials for railway axles: EA1N and EA4T steels. Obtained results could be used for safer operation of railway axles.

železniční náprava, zbytková únavová životnost, únavová trhlina, zátěžné spektrum, EA1N, EA4T

railway axle; residual fatigue lifetime, fatigue crack; load spectrum; EA1N; EA4T

2014

18.06.2014

Elsevier

1877-7058

74

1

313–316

4