Fracture mechanism and control method of elastic strip of Cologne-egg fastener in the high-prevalence section of rail corrugation

Abstract

Rail corrugation is a typical problem on rail surface, and its high-prevalence section is often accompanied by the fracture of fastener elastic strip. The present paper focuses on the fracture mechanism and control method of the Cologne-egg fastener elastic strip in the high-prevalence section of rail corrugation. Firstly, the numerical simulation model of wheel-rail-fastener system considering the key components of Cologne-egg fastener is completely constructed. Then, the fracture mechanism of Cologne-egg fastener is explored by comprehensively considering the resonance response and fatigue failure of the fastener elastic strip. Finally, the corresponding control methods are proposed by the passive control of rail grinding and active adjustment of fastener structure. Analysis results show that the intensified wheel-rail friction coupling vibration in the corrugation zone leads to the resonance response of the Cologne-egg fastener elastic strip, which intensifies the vibration response of elastic strip. Then, the aggravation of vibration response of the Cologne-egg fastener elastic strip leads the fatigue of the elastic strip, and the outer elastic strip is easier to fracture than the inner elastic strip on the low rail of small-radius curve. Controlling the corrugation depth before 0.16 mm or adjusting the elastic modulus of the damping rubber to be 2.20 MPa and 9.40 MPa can increase the service life of Cologne-egg fastener elastic strip.