Study On The Stress Transmission Characteristics Of Rail Under The Vertical Vibration Of Different Frequencies

Tests show that some kinds of rail defects have a relation on vibration and impact that with special frequencies, so it’s necessary to research the rail stress characteristics and its transmission characteristics under different frequencies. On the basis of summing the force status in rail, the rail stress calculation models and the research on rail vibration transmission characteristics all over the world, this paper established a120m-long rail solid finite element model, then used stress transfer function, stress contour, stress vector diagram and mode shapes between0-2000Hz to study the stress transmission characteristics of rail under the vertical vibration of different frequencies. The paper analyzed the rationality of rail Euler beam model, Timoshenko beam model and long solid model under different frequencies, and considered the influence of effect on different positions, vertical stiffness under rail, vertical damping under rail on rail stress transmission characteristics.According to the analysis, the rail stress state has a relation with the frequency and has a large difference with the static results. The bending stress and shear stress of rail show different rules of stress states with different frequencies, and the shear stress state of different directions is also affected by the frequency. From the view of stress, Euler beam model and Timoshenko beam model are only applicable for stress analysis before the rail resonates. When the frequency is larger than the resonance frequency of the rail, the stress amplitude swings violently and the results are not agreed with the results of solid model. As to solid model, the results with the force points on the sleeper and force points between the sleepers are different, and the results have different rules with different frequencies. Under different frequencies, the impact of the vertical stiffness under the rail to the bending stress state shows different rules. And it has a relation with the force points location and section position, but it has a large difference with the bending stress state under static loadings. The impact of vertical stiffness under the rail to the shear stress state of different directions shows different rules under different frequencies. The impact of vertical damping under rail to the bending stress state shows different rules under different frequencies.In this paper, it’s the first time to analyze the rules that the rail stress state changing with the frequencies and the result provides a theoretical basis for the future research on the rail defects with frequencies.