Simulation dynamic processes of rail vehicle and rail with irregularities

The work presents research of defective railway wheel and rail dynamics and mathematical model of system “Railway vehicle wheel – track”. An assumption was made that the Rail R–65 and railway wheel with flats are with unevenness. The aim of this investigation is to identify the contact forces resulting from the wheel/rail contact at the various defects. Rail track dynamics is described by finite element method, while soil and wagon dynamics is described by the discrete elements. The mathematical model is to assess physical and mechanical properties, roughness of wheel and rail surface, and their geometry. In the mathematical model of the rail is evaluated: the impact of axial force, the initial deformation of rail, the foundation of soil, the gap between sleeper and rail. Profile of railway wheel is defined as a function of radius variable depending on the polar angle and described by Fourier series. In this mathematical model of railway wheel and rail contact area is divided into small sections, where the force is set in contact using the Hertz theory. Total system of non-linear equations of motion is solved by applying the Newton-Raphson method. The speed of the train is 100 km/h and static load on the rail is 100 kN. The flat of the wagon wheel is L=100 mm. Numerical results of contact problem are obtained. Duration of contact is nearly equal to period during which the wheel set passes a half of the flat length. The contact force operating the wheelset is equal to approximately 1.0 MN. Maximum value of the sleeper acceleration is equal 410 g.