STRESS-STRAIN STATE ASSESSMENT OF THE BOGIE FRAME OF DPKR-2 DIESEL TRAIN UNDER ACTION OF DESIGN AND OPERATIONAL LOADS

Abstract

Purpose. The article is aimed to ensure the operation safety, increase in the strength and durability of the most loaded supporting elements of rolling stock – bogies, in particular the bogies of the DPKr-2 diesel train. Methodology. In order to assess the design strength of the bogie prototype, a spatial solid-state 3D model was constructed. Using the software package implementing the finite element method, the most loaded nodes of the bogie frame are determined based on the Palmgren–Miner–Mises theory. During the finite element modeling, the peculiarities of the design work in operation, the action of static loads and the corresponding dynamic additives are taken into account. The results of calculation were used to develop the layout diagram of the strain gauges on the bogie frame during the running strength tests. According to their results, the fatigue strength of the bogie frame prototype under the action of operating loads was estimated and a conclusion was made about the need to strengthen its design. The design management of the PJSC «Kryukov Railway Car Building Works» proposed the variant of enhancing the bogie frame prototype. Findings. Based on the results of theoretical and experimental studies, the prototype design of the DPKr-2 diesel train was modernized, which made it possible to reduce stresses in the most loaded nodes and significantly increase its durability. Strength calculations and running strength tests of diesel trains with modernized bogies were carried out. Originality. For the first time, a spatial finite element model of the new generation diesel train was constructed and the strength calculation was carried out under the action of design loads. The constructed model made it possible to choose the variant of modernizing the frame prototype that satisfies the fatigue strength conditions. The conducted experimental studies have shown the efficiency of modernization, in particular the increase in strength and durability of the design. Practical value. The complex of design and experimental work on the assessment of the stress-strain state of the bogie frame of the DPKr-2 diesel train under the action of design and operating loads allowed creating a design that satisfies both the operational requirements and the requirements of strength and durability. The developed design of the bogie frame makes it possible to increase the operation safety and can be used in the next generation diesel trains.