A train experiences different slip ratios at the wheel/rail contact point
as it moves along the rail track, which influences the rolling contact
fatigue (RCF) and wear properties of wheel and rail materials. This
variation in slip ratios is caused by a change in contact area between the
wheel and rail head at curves, as the slip ratio increases compared with
when a train is moving on a straight track. When the train is moving on
a straight track, the wheel is found to be in contact with the rail head;
but that changes when moving around curves, as the wheel flange will
now be in contact with the gauge corner of the rail, affecting the
severity of wear. Therefore, more research needs to be done to
understand the role that slip ratio plays in the wear performance of
wheel and rail materials in order to be able to develop models or systems
that could be used to predict preventive maintenance. The aim of this
work was to investigate the effect of the slip ratio on the wear
performance of class B wheels against softer R260 rail steels under
rolling and sliding conditions, using a twin-disc setup developed at the
University of Pretoria. The results showed that the severity of wear was
heavily dependent on the slip ratio – i.e., it increased with the slip ratio,
with class B wheels performing better than the softer R260 rail.
’n Trein ervaar verskillende glipverhoudings by die wiel/spoorkontakpunt
soos dit langs die spoorlyn beweeg, wat die
rolkontakmoegheid (RCF) en slytasie-eienskappe van wiel- en
spoormateriaal beïnvloed. Hierdie variasie in glipverhoudings word
veroorsaak deur 'n verandering in kontakarea tussen die wiel en spoorkop
by kurwes, aangesien die glipverhouding toeneem in vergelyking met
wanneer 'n trein op 'n reguit spoor beweeg. Wanneer die trein op 'n
reguit spoor beweeg, word gevind dat die wiel in kontak is met die
spoorkop; maar dit verander wanneer om die trein om kurwes beweeg,
aangesien die wielflens nou in kontak sal wees met die spoorhoek van
die spoorstaaf, wat die hoeveelheid slytasie beïnvloed. Daarom moet
meer navorsing gedoen word om die rol wat glipverhouding speel in die
slytasieprestasie van wiel- en spoormateriaal te verstaan, ten einde
modelle of stelsels te kan ontwikkel wat gebruik kan word vir die
voorspelling van voorkomende instandhouding. Die doel van hierdie werk
was om die effek van die glyverhouding op die slytasieprestasie van klas
B-wiele teen sagter R260 spoorstaal onder rol- en glytoestande te
ondersoek, met behulp van 'n tweeskyf-opstelling wat by die Universiteit
van Pretoria ontwikkel is. Die resultate het getoon dat die erns van
slytasie baie afhanklik was van die glipverhouding - dit wil sê, dit het
toegeneem met die glipverhouding, met klas B-wiele wat beter presteer
as die sagter R260-reling.
