Investigation of Coupling Strength at Non-Central Interaction of Railcars

The strength of the coupling device under the action of operating loads with regard to the non-central interaction of two cars is defined. When longitudinal force is transmitted through the coupler, the points of its possible rotation can be either the upper ribs of the shank end surface or the upper ribs of the damping device body support surface. The tail part of the coupler is under conditions of eccentric compression (or tension) by the force, which is non-parallel to the longitudinal axis. Through any cross-section of the shank, transverse and longitudinal forces are transmitted, applied at a point far from the center of gravity of the section. Using the principle of addition of forces action, a dependence for the definition of the maximum normal stresses in the extreme fibers of the analyzed section of the shank of the coupler, the most distant from the main axis of inertia, has been obtained. The damage to the area of the coupler shank jumper and the bending of the shank in the horizontal and vertical planes, which occur during operation, are justified. Calculation methods make it possible to study the influence of eccentricities of longitudinal force application relative to the coupler axis and the difference of coupler axis levels in the analyzed sections on the magnitude of the compressive operating loads. Application of the obtained results will not only help to ensure the strength of the coupling devices, but will also ensure the freight cars’ durability under conditions of increasing train weight and increasing train speed.