|
|
Experimental Study of the Efect of Lubricants on Rolling Contact Life
Šembera, Václav ; Ficza, Ildikó (referee) ; Nohál, Libor (advisor)
The aim of this bachelor’s thesis is to summarize the art of state in the area of the contact fatigue, lubricants and detection of the rolling contact fatigue exploiting the acoustic emission method. In the experimental part of this bachelor’s thesis are performed the rolling contact testing for the standard grease and the lubricant with EP additives by marginal exploiting the acoustic emission method. The effect of the lubricants on the rolling contact life is evaluated by basic rating life L10 stated by using Weibull distribution.
|
|
|
Numerical Simulations of Dynamic Loads in Wheel-Rail Contact with Shape Irregularities
Jandora, Radek ; Malenovský, Eduard (referee) ; Schmidová, Eva (referee) ; Janíček, Přemysl (advisor)
During life of railway vehicles, shape irregularities develop on wheels and rails because of wear. The shape irregularities then affect forces in wheel-rail contact and cause further damage of contact surfaces, vibrations and noise and increase risk of derailment. A numerical simulation of railway vehicle motion with more details on contact surfaces geometry was created to investigate dynamic contact loads in wheel-rail contact. A variety of methods can be used to evaluate forces in rolling contact, the method chosen for this study was algorithm CONTACT based on boundary element method. Four studies are presented in this papers: contact loads from a wheel with a flat and with a wavy tread pattern, loads on wavy rail and load in a curve. The first three studies investigated effects of existing wear patterns, the last one looked for cause of common wear pattern developing on rails. Results of the studies with worn components used showed that the worst kind of shape irregularities is a flat present on wheel. This type of shape cause loss of contact and following impacts. The study of ride in curve showed that cause of high wear in curves, especially those with small radii, is caused by vibration of wheelset. This vibration is then caused by different length of inner and outer rail and wheels travelling along a different path.
|
|
|
Numerical Simulations of Dynamic Loads in Wheel-Rail Contact with Shape Irregularities
Jandora, Radek ; Malenovský, Eduard (referee) ; Schmidová, Eva (referee) ; Janíček, Přemysl (advisor)
During life of railway vehicles, shape irregularities develop on wheels and rails because of wear. The shape irregularities then affect forces in wheel-rail contact and cause further damage of contact surfaces, vibrations and noise and increase risk of derailment. A numerical simulation of railway vehicle motion with more details on contact surfaces geometry was created to investigate dynamic contact loads in wheel-rail contact. A variety of methods can be used to evaluate forces in rolling contact, the method chosen for this study was algorithm CONTACT based on boundary element method. Four studies are presented in this papers: contact loads from a wheel with a flat and with a wavy tread pattern, loads on wavy rail and load in a curve. The first three studies investigated effects of existing wear patterns, the last one looked for cause of common wear pattern developing on rails. Results of the studies with worn components used showed that the worst kind of shape irregularities is a flat present on wheel. This type of shape cause loss of contact and following impacts. The study of ride in curve showed that cause of high wear in curves, especially those with small radii, is caused by vibration of wheelset. This vibration is then caused by different length of inner and outer rail and wheels travelling along a different path.
|
|
|
Numerical Simulations of Dynamic Loads in Wheel-Rail Contact with Shape Irregularities
Jandora, Radek ; Janíček, Přemysl (advisor)
During life of railway vehicles, shape irregularities develop on wheels and rails because of wear. The shape irregularities then affect forces in wheel-rail contact and cause further damage of contact surfaces, vibrations and noise and increase risk of derailment. A numerical simulation of railway vehicle motion with more details on contact surfaces geometry was created to investigate dynamic contact loads in wheel-rail contact. A variety of methods can be used to evaluate forces in rolling contact, the method chosen for this study was algorithm CONTACT based on boundary element method. Four studies are presented in this papers: contact loads from a wheel with a flat and with a wavy tread pattern, loads on wavy rail and load in a curve. The first three studies investigated effects of existing wear patterns, the last one looked for cause of common wear pattern developing on rails. Results of the studies with worn components used showed that the worst kind of shape irregularities is a flat present on wheel. This type of shape cause loss of contact and following impacts. The study of ride in curve showed that cause of high wear in curves, especially those with small radii, is caused by vibration of wheelset. This vibration is then caused by different length of inner and outer rail and wheels travelling along a different path.
|
|
|
Experimental Study of the Efect of Lubricants on Rolling Contact Life
Šembera, Václav ; Ficza, Ildikó (referee) ; Nohál, Libor (advisor)
The aim of this bachelor’s thesis is to summarize the art of state in the area of the contact fatigue, lubricants and detection of the rolling contact fatigue exploiting the acoustic emission method. In the experimental part of this bachelor’s thesis are performed the rolling contact testing for the standard grease and the lubricant with EP additives by marginal exploiting the acoustic emission method. The effect of the lubricants on the rolling contact life is evaluated by basic rating life L10 stated by using Weibull distribution.
|
guest ::
