Удосконалення несучих конструкцій вантажних вагонів шляхом використання наповнювачів в їх складових

Abstract

UA: Дисертаційна робота присвячена вирішенню актуального наукового завдання для залізничного транспорту – удосконаленню несучих конструкцій вантажних вагонів шляхом використання наповнювачів в їх складових. Для зменшення динамічної навантаженості несучих конструкцій вантажних вагонів запропоновано використання замкнених профілів хребтових балок, заповнених наповнювачем. Результати розрахунків динамічної навантаженості та міцності несучих конструкцій основних типів вантажних вагонів підтвердили доцільність запропонованого удосконалення. Також в роботі наведено результати теоретичного обґрунтування створення концепту несучої конструкції напіввагона з випуклими стінами. Встановлено, що така конфігурація бокових стін дозволяє підвищити корисний об’єм кузова на 8% у порівнянні з вагоном-прототипом. Проведено експериментальне дослідження міцності пустотілих стрижнів замкненого перерізу, а також з наповнювачем. Здійснено техніко-економічне обґрунтування запропонованих рішень щодо удосконалень несучих конструкцій основних типів вантажних вагонів. Отримані результати розрахунків підтвердили доцільність прийнятих рішень. EN: The thesis is devoted to the solution of the urgent scientific problem for railway transport, i.e. how to improve the bearing structure of a freight car by applying filler in its components. The study proposes the application of filler for the closed profiles of the center sill in order to decrease the dynamic loading on the bearing structure of a freight car. The calculation was made for main types of freight cars and included elastic, viscous, and elastic-viscous fillers. The results of calculation demonstrated that the application of viscous or elastic-viscous fillers is the most efficient technological solution regarding lower dynamic loading and better performance of a freight car. With viscous filler applied the maximum accelerations to the bearing structure of an open car were 36.8 m/s2 . This value is 4% lower than that obtained for the bearing structure without filler. The research also deals with the computer modeling of the dynamic loading on an open car with filler in the bearing structure. The calculation was made with the finite element method in SolidWorks. It was found that the maximum accelerations were concentrated in the middle part of the open car frame; they were about 38 m/s2 . The models of dynamic loading on an open car with filler in the bearing structure were verified. Besides, the research presents the results of the theoretical substantiation for the concept of the bearing structure of an open car with convex sidewalls. It is found that such a sidewall profile can improve the useful capacity of the body by 8% in comparison with that for the prototype car. The strength of the bearing structure of an open car with convex sidewalls was also determined. It was found that the maximum equivalent stresses occurred during Design Mode I (impact) in the contact area between the center sill and the body bolster; they amounted to about 340 МPа and did not exceed the allowable values. The basic dynamic characteristics for the bearing structure with convex sidewalls were also calculated. The maximum accelerations on the bearing structure of an open car in the center of mass did not exceed the allowable values; they amounted to about 0.4g. Other dynamic characteristics were also within the allowable values. And the motion was estimated as excellent. The design service life of the bearing structure of an open car with convex sidewalls was calculated as no less than 32 years. It was offered to apply filler in the closed-section center sill to reduce the dynamic loading on the bearing structure of the open car concept with convex walls. It was found that the maximum equivalent stresses during Design Mode I (impact) occurred in the contact area between the center sill and the body bolster; they amounted to about 315 МPа. The value of maximum equivalent stresses obtained was 7% lower than that obtained for the bearing structure without filler. The application of fillers in the components of the bearing structure of a car with the closed cross-section was substantiated by means of the experimental research into the strength of empty closed cross-section pipes and ones with filler. It is found that filler can decease stresses in the pipes by 5.3% in comparison with those occurred in the structure without filler. The research also presents the feasibility study of the solutions on improvements in the bearing structure for the main types of freight cars. The results of calculation confirmed the efficiency of the solutions implemented. The economic benefit can be gained by means of lower costs of out-of-schedule repairs of freight cars. The research conducted may contribute to higher operational efficiency of railway transport by means of lower maintenance cost and better efficiency, and through collection of exploratory studies on designing innovative structures of rolling stock.