Experimental Study On Corrugated Wear Of A Sliding Surface Caused By Frictional Self-Excited Vibration

After a new railway line is put into operation for a period of time, some positions of the top working surface of the railway rail would be suffered from some regular and periodical wear which is quasi-sinusoidal irregularities. This phenomenon is called as rail corrugation. The rail corrugation is one of the main reasons for the damage of the components of vehicles and tracks, noise and vibration of wheel-rail. And it is also one of the important problems difficult to solve in the wheel-rail contact relation.In the paper, a series of experimental tests were conducted on a pin-on-disc tester to study the effect of frictional self-excited vibration on evolution of the scar profile. The profiles of the worn surfaces of the disc specimen were measured. The power spectrum method was used to investigate the fractal behavior of the wear scars of disc specimens under different test conditions. In the present test, a phenomenon of forced corrugation was reproduced with the disk/pin friction couples whose materials are10440wheel steel and U71Mn rail steel to validate the dynamic formation mechanism of corrugation. The study leads to the following conclusions:(1) The fluctuation of the normal force between the disc and pin contact surfaces is considered to be responsible for the generation of the corrugated wear. In the sliding area with a high normal force, wear and plastic deformation of the disc specimen material are serious, thus troughs are formed. In the sliding area with a low normal force, wear and plastic deformation of the disc specimen material are light, thus peaks are formed.(2) The fluctuation of friction work caused by friction self-excited vibration is the main reason for the corrugated wear of the plate specimen.(3) The wavelength of corrugated wear is approximately equal to the sliding speed multiplied by the period time of the friction-induced vibration.(4) The fractal dimension of the corrugated scars of the disc specimen is D=1.79-1.92. The larger the value of fractal dimension, the more serious the corrugated wear of the disc specimen and the longer the wavelength of corrugated wear is.(5) The corrugated scars of the disc specimen have obvious fractal characteristics and their fractal dimensions are changed with the sliding speed, normal load and test time.(6) Under the same normal load, the value of fractal dimension increases with the increasing of the sliding speed. Under the same sliding speed, the value of fractal dimension increases with the increasing of the normal load. Under the same speed and load, the value of fractal dimension decreases with the increasing of the test time.