Розвиток наукових основ розрахунків конструкцій вагонів шляхом урахування наднормованих режимів при експлуатації

Abstract

UA: Ловська А. О. Розвиток наукових основ розрахунків конструкцій вагонів шляхом урахування наднормованих режимів при експлуатації. – Рукопис. Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.22.07 – рухомий склад залізниць та тяга поїздів (273 – залізничний транспорт); Український державний університет залізничного транспорту, Харків, 2021. Дисертаційна робота присвячена вирішенню актуальної наукової задачі для залізничного транспорту – розвитку наукових основ розрахунків конструкцій вагонів шляхом урахування наднормованих режимів при експлуатації та їх удосконалень. Запропоновано методи розрахунків динамічної навантаженості та міцності несучих конструкцій вагонів при наднормованих режимах: перевезення поїздів комбінованого транспорту на залізничних поромах, а також маневрові співударяння вагонів, в тому числі вагонів-платформ, завантажених контейнерами або контейнерами-цистернами. Обґрунтовано впровадження принципів мультифункціональності та мультиматерільності на стадії проектування несучих конструкцій вагонів, контейнерів, а також контейнерів-цистерн. Проведено експериментальне дослідження міцності несучої конструкції вагона-платформи з контейнерами із урахуванням типової схеми взаємодії фітингів з фітинговими упорами, а також при пружній. Проведено техніко-економічне обґрунтування запропонованих рішень щодо удосконалень несучих конструкцій вагонів та контейнерів при наднормованих режимах навантажень. Отримані результати розрахунків підтвердили доцільність прийнятих рішень. EN: Lovska A. O. Development of scientific foundations for calculating wagon structures by taking into account the above-norm cases of their operation. – Manuscript. Dissertation for the degree of Doctor of Technical Sciences in the speciality 05.22.07 – rolling stock of railways and train traction (273 – railway transport); Ukrainian State University of Railway Transport, Kharkiv, 2021. The thesis is devoted to solving a relevant scientific problem for railway transport – the development of scientific foundations for calculating wagon structures by taking into account the above-norm cases of their operation and improvements. In this regard, in the dissertation work, methods for calculating the dynamic loading and strength of the load- bearing structures of wagons in the following above-norm cases are proposed: transportation of combined transport trains on railway ferries and shunting collision. For the first time, a procedure was proposed for taking into account the above-norm cases of dynamic loading of the load-bearing structures of wagons in operation (transportation of flat wagons with containers (tank containers) on railway ferries). This made it possible to form the basic requirements for the safe operation of wagons under these conditions, as well as to propose measures to improve their designs. These improvements consist in the use of viscous connections in the interaction of combined transport vehicles with each other to reduce dynamic loading during operation: the use of a viscous tie between the load-bearing structure of the wagon and the deck of the railway ferry, the use of flat wagons with superstructures having a viscous connection with the side walls of containers. To reduce dynamic loading of the load-bearing structures of the flat wagon and containers, as well as tank containers, the use of elastic, viscous or viscoelastic connections between fitting supports and fittings is proposed. The proposed solutions are

substantiated by the results of mathematical and competer modelling of dynamic loading of the flat wagon loaded with containers and tank containers during shunting collision, taking into account the loading of 3.5 MN acting on the rear support of the automatic coupler. Verification of the developed models of dynamic loading is carried out. The results of scientific substantiation of implementation of the concept of an automatic coupler harness in the load-bearing structures of wagons made of round pipes, as well as articulated wagons, created on the basis of wagons made of round pipes, are presented. It is established that acceleration acting during shunting collision on the load- bearing structure of a wagon equipped with the concepts of harnesses is lower by 10% than acceleration values obtained in case of the typical scheme of load supported by the spine beam of the wagon. Principles of multifunctionality in the design of load-bearing structures of wagons are proposed. These principles are implemented in the load-bearing structures of wagons made of round pipes by using energy-absorbing material as filler of their components. It is also proposed to use elastic and frictional connections in the load-bearing structures of wagons to reduce dynamic loading and increase fatigue strength. This solution is implemented in the load-bearing structures of a gondola car, a long-base structure of a flat wagon, as well as a covered wagon. The research results showed that taking into account the proposed solutions it becomes possible to reduce dynamic loading of the load-bearing structures of wagons in comparison with prototype wagons: the gondola car – by 25%, the flat wagon – by 15%, the covered wagon – by 20%. Experimental studies of the strength of the wagon load-bearing structure were carried out taking into account the proposed improvements. At the same time, field studies of the strength of the load-bearing structure of the flat wagon with containers are carried out, taking into account the typical scheme of interaction, as well as elastic one. The research is conducted using the method of electric strain gauging. The tests are carried out in accordance with the developed "Test programme and methods". The mounting locations of strain gauges on the load-bearing structure of the flat wagon are determined by the results of theoretical calculations and the obtained stress distribution fields. In this case, strain gauges with a base of 10 mm and resistance of 200 Ohms are used. The studies are conducted in the range of collision speeds: 3 – 6 km/h, 6 – 10 km/h and more than 10 km/h.The results of the conducted research allowed determining the specified values of strength indicators of the flat wagon load-bearing structure and confirm the results of theoretical research. The maximum discrepancy between the results of mathematical and physical experiment in the typical scheme of interaction of the flat wagon with containers is 17.0%, and in the elastic one – 17.5%. All the solutions proposed in the work to improve the load-bearing structures of wagons have a feasibility study. The scientific and practical results of the dissertation work are the basis for the creation of innovative designs of wagons, which make it possible to increase the efficiency of the operation of railway transport.