Substantiating the Optimization of the Load-bearing Structure of a Hopper Car for Transporting Pellets and Hot Agglomerate

The strength parameters have been determined for the bearing structure of a hopper car used to transport pellets and hot agglomerate. The calculation was based on a finite element method, implemented in the software COSMOSWorks. Strength reserves of load-bearing elements in a carbody have been determined. In order to reduce material consumption for a carbody, it has been proposed to use pipes with a circular cross-section as the bearing elements. Mathematical modeling was applied to determine the accelerations that act on the optimized bearing structure of a wagon when it is struck at shunting. It has been established that the accelerations that act on the bearing structure of a wagon amount to 42.4 m/s2 (4.3 g). The derived acceleration magnitude was accounted for when calculating the strength of a hopper car's bearing structure. The maximum equivalent stresses in this case reached about 270 MPa and were concentrated in the region where a girder beam interacts with a pivot beam while not exceeding the permissible ones for the grade of steel used in the metallic structure.We have simulated the vertical dynamics of the optimized bearing structure of a hopper car used to transport pellets and hot agglomerate. During calculations, the parameters for a spring suspension of the 18-100 model's undercarriage were taken into consideration. The results of our calculations make it possible to conclude that the accelerations of a hopper car body, as well as undercarriages, are within the allowable limits. In this case, in terms of compliance with the requirements of normative documents, the car ride quality can be described as «excellent».The proposed technical solutions justify the use of round pipes as the load-bearing elements of a hopper car body for transporting pellets and hot agglomerate. In this case, it becomes possible to reduce the hopper car tare by almost 5 % compared to a prototype car. In addition, the introduction of round pipes in the bearing structure of a hopper car could bring down manufacturing costs for railroad car building enterprises.Our study would contribute to the construction of modern structures of hopper cars, as well as to the improved efficiency of railroad transportatio