Study On Mechanism And Simulation Experiment Of The Influences Of Railroad Wagon Loading Conditions On Vehicle Running Safety

Wagon loading conditions are the important factors influencing railway safety. Wagon loading conditions are governed by the cargo weight and the location of cargo gravity center at the lateral, longitudinal, and vertical directions. With the improvement of railway line and innovation of railway infrastructures and equipments, the rules of China’s wagon loading technical conditions have already been out of date, which need to be systematically studied.Focusing on the influences of wagon loading conditions on railway vehicle running safety, this paper includes the following contents:(1) Based on determining wagon loading condition parameters, including cargo mass (CM), height of gravity center of a loaded wagon (CGHL), longitudinal deviation of cargo gravity center (CGCLoD) and lateral deviation of cargo gravity center (CGCLAD), the factors influencing railway vehicle running safety are qualitatively analyzed.(2) According to the static analysis method, the interactions between cargo, vehicle and rail are analyzed. Then the static equations of wagon loading condition parameters and railway vehicle running safety indexes (overturning coefficient, derailment coefficient and wheel unloading rate) are established in cases of wagons are running on the straight lines, curve lines with overbalanced superelevation and curve lines with underbalanced superelevation. Through the multiple regression method, taking the wagon C70H for example, the equivalent formulas of the influences of wagon loading condition parameters on overturning coefficient, derailment coefficient and wheel unloading rate are deduced. Then the mechanism of the influences of wagon loading condition parameters on railway vehicle running safety indexes is studied.(3) According to the vehicle system dynamics and the D’Alembert’s principle, the equations of motion of the railway wagon considering the coupling of cargo and vehicle are established.(4) Depended on the multibody dynamics software SIMPACK, the cargo-vehicle-rail simulation model of wagon C70H is established. Then this model is testified to be reasonable after comparing the results of simulation model with the practical dynamic tests of C70H running on the straight lines and curve lines.(5) By setting specific calculation scenarios of wagon loading and running conditions, a large number of simulation calculations are done, then the influences of CM, CGHL, CGCLOD and CGCLAD on overturning coefficient, derailment coefficient and wheel unloading rate are studied, respectively. According to the results and potential rules, the range of the wagon loading condition parameters guaranteeing railway vehicle running safety is determined.