Light Weight Freight Rolling Stock Bogie Frame:Design Methodology Validated with Field Oscillation Trials

Indian railway has improved the laden to tare weight ratio by producing lighter as well as higher strength bogie frame of freight rolling stock. Bogie frame is the crucial component of the rail vehicle which carries static load in the form of gross weight and dynamic loads arising from various track and wheel irregularities. The three piece freight vehicle bogie frame comprises two side frames and one bolster. The side frame; fitted with three piece bogie frame and responsible for the ride quality of the freight vehicle, is considered in present study. The locations suitable for weight reduction are found by finite element analysis (FEA), using side frame solid model in MSC FEA environment. International standards of the association of American railroad (AAR specification M-203) load cases and boundary conditions are deployed for analysis in the context of the operating scenario of Indian railways. Typical Indian railway track signatures are used as input for transient analysis. Time dependent stresses at critical speeds are used for fatigue strength evaluation as per Goodman diagram. The modified design is approx. 13.90% lighter and sustains 25.00 ton axle load in comparison of earlier 22.00 ton. Suggested topological changes have been compared by using frequencies of the initial and modified designs. Further, based on Indian railways running conditions, actual assessment and trial of the modified design bogie frame prototype has been carried out by Research Designs and Standards Organisation (RDSO). The results of the trial are found to be satisfactory and within the prescribed range.