Experimental Study of Dynamic Forces Acting on Wheel Pairs of Railway Rolling Stock in Operation

Abstract

AbstractThe efficiency of rail transport directly depends on train speeds and axle loads of rolling stock, the increase in which causes an increase in the level of dynamic forces acting on wheel sets and rails. As a result of the wheels interaction with defects in the rolling surface and rails in the process of operation, the dynamic forces increase significantly, which negatively affects both the probability of formation and the rate of defects development in the parts of wheel sets and axlebox units. The research purpose is to create a technique and experimental determination of statistical distribution parameters of vertical dynamic forces arising in real operating conditions in the system of wheel and rail using dynamic tensometry. The equipment for vertical forces control, acting from the wheels of the rolling stock on reinforced concrete sleepers, is installed on the existing section of a straight railroad track on the rails. A methodology of strain-gauge control, based on measuring vertical deformations of rail necks above the sleepers and the software for determining the vertical forces in the “wheel-rail” system have been developed. The equipment was created and the strain gauge control section was calibrated under static (hydraulic jack) and dynamic (impact) loading. In the process of repeated tests with train load and in real operating conditions, the distribution of vertical dynamic forces arising in the “wheel-rail” system when the train moves were obtained. It is shown that the presence of even permissible defects of the rolling surface increases the dynamic forces by 2–3 times, the distribution of these forces is approximated by the exponential dependence and the probabilities of their occurrence in the train are calculated.KeywordsDynamic forces“wheel-rail” systemWheel surface defectsReliability of railcars running partsDynamic tensometryControl of wheels in motion