Abstract: An investigation into the corrugation mechanism of rails in both tangent and curved tracks of a metro with Cologne fasteners is carried out through a detailed observation, an extensive measurement at sites and a numerical analysis. The rail corrugation presents the three different wavelengths which are respectively 20 mm,40 mm to 50 mm and 200 mm. The uneven wear of 40 mm to 50 mm is dominant in the corrugation development. In the investigation, first, a relationship between the characteristics of the rail corrugation and the track structure is analyzed based on the field measured data of the rail corrugation and the modal test of the track by using hammer knocking. Then a three-dimensional numerical model for the track is established by using finite element code ABAQUS to further verify such the relationship. The results are obtained by the numerical method coincide with those of the field tests. Through extensive field experiments and detailed theoretical analysis, the mechanism of the corrugation is understood basically and the resonance of the metro track mainly plays an important role in the rail corrugation generation. The numerical model is also used to analyze the effect of the stiffness and damping of the fasteners on the track resonances and the stiffness and damping of the Cologne fasteners have a great influence on the rail corrugation.

Key words: Dynamic characteristic, Fastener, Finite element method, Rail corrugation, Slab track, Stiffness and damping