PSI - Issue 59

O. Fomin et al. / Procedia Structural Integrity 59 (2024) 516–522 2 Oleksij Fomin, Pavlo Prokopenko, Yevhenii Medvediev, Larysa Degtyareva / Structural Integrity Procedia 00 (2023) 000 – 000 1. Introduction Ensuring traffic safety is one of the most important requirements for the operation of railways. Among the accidents and disasters in railway transport, derailment is the most dangerous, as it can lead to serious consequences. The reasons for the derailment of light-weight freight cars are the breakage of the side frames and spring beams of the bogies, the breakage of axles and wheels, malfunctions of the roller bearings of the skid assembly, wear of the elements of the friction dampers and the unit supporting the body on the spring beams, unacceptable deviations in the dimensions of the bogies. Also, an important reason is the negative reduction of the wagon's tare by more than 10% from the one set by the manufacturer, which is relevant for light-weight wagons after long-term operation. Among the light-weight wagons most often derailed are empty platform wagons and hopper wagons for cement. To assess the quality indicators, the safety of the movement of wagons, locomotives, and other types of rail rolling stock, a variety of approaches to the assessment of safety conditions and the solution of the specified problem are noted. The work (Kondrat'yev, 1980) is devoted to the derailment problem, which proposes to reduce the initial system of forces acting on the wheel pair to a simpler, equivalent system. Here, the author distinguishes wheel pairs according to the mode of movement and investigates the influence of this factor on the derailment process. A combined criterion for the purpose of assessing the danger of a rolling stock derailment due to the rolling of a wheel on the head of the rail is proposed (Pogorelov et al., 2009; Pogorelov et al., 2010). Here, instead of the coefficient of friction, it is proposed to use the ratio of the transverse component of the force to the normal reaction at the contact point. The authors suggest directly using wheel lift values above the rail head to assess the danger of derailment, starting from the position at which the ridge contact is first detected at the point where the angle of inclination forms the ridge profile is max. The paper (Azovsky et al., 2007) formulates the energy interpretation of the rolling of the wheel on the head of the rail. According to the authors, this is possible when the kinetic energy of the movement attributable to the wheel pair running into the rail exceeds the work of the forces arising in the contact between the surfaces of the ridge and the wheel, which they perform when rising to the height of the ridge. In the work (Koturanov et al., 2010), the authors developed a refined method for determining the danger of derailment, where at each step of integration in the process of computer simulation of the movement of the rolling stock, the procedure of comparative evaluation of the values of the three coefficients of the stability reserve, calculated according to the Mariet formula. The paper (Fomin et al., 2015) presents the features and results of cataloging a gondola-carrying system by applying this approach to the face wall of one of the basic models of gondolas. The article (Fomin et al., 2018) describes the main types of residual deformations due to thermal effects during the welding of car bodies. It is noted that the issues of eliminating these deformations in production and maintenance are becoming more and more urgent. In particular, the industry's most recognized and economically oriented approach is based on the thermal alignment of welded structures. The article (Kehlrich et al., 2019) describes the results and features of control tests of tank cars for transporting particularly dangerous goods. As a result of the work, a conclusion was made about the possibility of continuing the operation of such wagons. Authors (Fomin et al., 2015) highlighted the results of work on determining ways to increase the degree of ideality of freight cars and forecasting the evolution of the chassis of new-generation cars. A review of examples of the idealistic strategy of improving the undercarriage of railway universal freight semi-wagons. In the work (Gorbunova et al., 2019) the problem of insufficient braking power is highlighted and solved the problem by increasing the number of friction pairs, which leads to an increase in resource and labor intensity, unsprung mass, movement resistance, and low resource intensity. The problem of reducing the noise level when using friction brakes is also acute. The study of the dynamics of the elastic system of a spindle assembly type of a drilling-milling-boring center is described In the work (Krol et al., 2020). A three-dimensional model of the spindle assembly on rolling bearings was built. The design and calculation scheme of the spindle unit and the system of forces acting in milling the 517