Simulation of performance of subway wooden sleepers and determination of their tense state using Lira software complex

The article uses the software complex Lira for the calculation of wooden sleepers, in which the finite element method in the form of displacements is used. FEM provides for making a system of equations that is solved by considering each individual finite element, which is very easy to implement and thus is an important advantage of the method. The purpose of its use is to calculate the wooden sleepers for strength and to determine its bearing capacity. The following types of finite elements were chosen to simulate the upper track structure in the subway tunnel: universal rod-type spatial finite element (type 10) and universal finite element of spatial problem of the elasticity theory (type 31). To design a spatial model, a section of the rail with seven sleepers in the subway tunnel was simulated and loaded with one axle of the car, since the influence of the adjoining sleepers on the estimated sleeper is negligible. They were divided into eight-node tetragonal parallelepiped-shaped finite elements. In order to simulate a sleeper encased in track concrete, a movement restriction was introduced at its points of contact with track concrete. The loads are applied to the rail above the middle sleeper symmetrically relative to its middle and are assumed as concentrated forces on each track line. The part of the sleeper above the culvert is not supported by track concrete and can move freely in all directions. To obtain the values of stresses, the maximum-stress theory of strength is used.