Features of skipping the work of railway metal superstructures, collection on curved sections of the track

Abstract

The article deals with the issues of the stress-strain state of the main load-bearing elements of a railway steel superstructure with ballast running, installed in a curved section of the track. To ensure movement in a curve, the path is laid with a variable eccentricity along the length relative to the axis of the superstructure. At the same time, due to the elevation of the outer rail, a force arises in the elements of the span structure due to the action of centrifugal force. Thus, the range of force effects from permanent and temporary loads on the main beams of such superstructures turns out to be quite complex.
The existing designs of railway metal superstructures with ballast running can be attributed to thin-walled rods. A characteristic feature of a thin-walled rod of a non-circular cross section is that during constrained torsion, longitudinal deformations and normal stresses proportional to this deformation occur in it. The magnitude of the stresses caused by constrained torsion depends on the bimoment acting in the section and the torsion stiffness of the structure.
The authors proposed an energy approach to determine the angle of twist of the section from the work of an external torque. Accounting for changes in the eccentricity of the action of external forces relative to the center of the bending of sections along the length of the span is made by expanding the loads in a Fourier series. This method allows you to apply any function of the torque from the coordinate along the length of the structure. Knowing the twisting angle of the section of the span structure, it is possible to determine the magnitude of the bimoment and, as a result, the values of normal stresses in the main beams bent in two planes under conditions of constrained torsion.