Model Test Of CWR Lateral Deformation Of Ballastless Track

Most high speed railways are ballastless track CWR. But Rails easily suffer from some little lateral irregularity under the significant temperature force of high temperature season, namely the small rail bending. Considering that ballastless track CWR stability theory is not complete, in order to research CWR lateral deformation regularity, the following studies are done through a combination of theoretical calculation and analysis and model test. In addition, the corresponding results are obtained.(1)According to the similarity theory and the similar proportion of 1:5, model test of CWR stability of ballastless track is designed, the test equipment is selected and the test method is worked out.(2)Any possible error that may happen in different stages is analyzed, and the model test is carried out according to the test plan. Tests show that when the lateral stiffness of the rail is small and temperature goes up to a certain degree, the rail will be in an unstable state and the weld defect position will be prone to be unstable than the fastener failure location. However, when the rail is in good condition and its lateral stiffness is large, the rail will change from much little lateral irregularity into a balance state. The lateral irregularity is called elastic irregularity.(3)Taking overseas and domestic experience obtained by studies on CWR stability of ballast track for reference, applying ballastless track WJ-7 type force transfer theory, the corresponding critical wavelength and force of different fasteners lateral resistance is obtained by energy method. In addition, the validity of applying energy method to deduce results is further proved by analyzing structure eigen buckling with finite element method.Studies show that the critical axial compressive force of ballastless CWR is far above the rail temperature force in extreme climate, which is not enough to result in the destruction of track structure. When the fastener lateral resistance is 30kN/mm and the rail is in good condition, complete sine wave elastic lateral irregularities will happen to rails and the wavelength is about 2.5m, which is identical to results of the model test with four-group fastener distance wavelength.