http://lib.kart.edu.ua/handle/123456789/28988 2026-07-12T20:01:20Z http://lib.kart.edu.ua/handle/123456789/32794 Title: Вплив структурних характеристик на стійкість бетону до динамічних впливів Authors: Плугін, Андрій Аркадійович; Палант, Олена Валентинівна; Плугін, Дмитро Артурович; Мірошніченко, Сергій Валерійович Abstract: The article deals with theoretical and experimental research into dependency of crack resistance of concrete under dynamic effects on coefficients of grain separation of coarse and fine aggregates. It was established that these dependencies were of extreme nature. The research yielded the optimal values of coefficients of grain separation of coarse and fine aggregates, cement particles, and also water-to-cement ratio for the materials under study; these factors provided the best physical and mechanical properties of concrete, including its crack resistance under dynamic effects, both impacts and vibrations. 2019-01-01T00:00:00Z http://lib.kart.edu.ua/handle/123456789/32793 Title: Вплив умов зберігання на електропровідність бетону Authors: Плугін, Андрій Аркадійович; Бабій, Анатолій Іванович; Плугін, Олексій Андрійович; Борзяк, Ольга Сергіївна; Калюжна, Олена Вячеславівна Abstract: Theoretical and experimental investigations of the influence of concrete moisture, its age, holding conditions after its thermal moisture treatment and other factors on the specific electric resistance of the concrete of a C32/40 grade used for reinforced concrete sleepers have been carried out. The obtained research data allowed us to specify holding modes and the duration of them and these enable the generation of objective information on the specific electric resistance of the concrete used for the sleepers during their operation. 2019-01-01T00:00:00Z http://lib.kart.edu.ua/handle/123456789/32792 Title: Дослідження процесу утворення та параметрична оцінка дуального зносу гальмових колодок вантажних вагонів Authors: Равлюк, Василь Григорович; Бондаренко, В’ячеслав Володимирович; Равлюк, Микола Григорович; Гребенюк, Віталій Анатолійович Abstract: The article presents a new scientific approach to the problem related to the specific nature of the adverse biplanar critical friction wear profile of brake pads which is quite common in cars of Ukrzaliznytsya JSC, as well as in many countries where the so-called three-element bogies are used. In the conducted studies, the concept of dual friction wear of brake pads was first discovered as a phenomenon and introduced. The stages of formation of especially harmful wear on the working surfaces of brake pads causing the complex formation of adverse specific dual wear are shown. A new concept of the duality coefficient of frictional wear of brake pads has been introduced, and a formula for its calculations has been proposed, which has been tested in the calculations of the values of brake pressures of pads with dual wear to support the analytical studies. 2019-01-01T00:00:00Z http://lib.kart.edu.ua/handle/123456789/32791 Title: Дослідження гібридної розрахункової схеми навантаження колодок гальмової важільної передачі вантажного вагона Authors: Равлюк, Василь Григорович; Бондаренко, В’ячеслав Володимирович; Равлюк, Микола Григорович; Гребенюк, Віталій Анатолійович Abstract: In the article, the points of load application effecting the pads and other parts of the freight car three-element bogie during braking is considered theoretically using the example of the 2D diagram of the brake rigging. The special differences between the operating conditions of the first and second triangles of the car brake rigging and their effect on the wear of the pads when the train is moving without braking are described. The different operating conditions of the triangles are described to establish a causal relationship regarding the abnormal wear of the brake pads of the three-element bogies. For the first time, a calculation algorithm of a more accurate approach to theoretical calculations was proposed to determine the actual 251 pressing forces in the brake pads on the wheels of the bogies. It proves the existence of the theoretical error, which is now inherent to the design models of freight cars brake rigging elements. The obtained algorithmic equations will help assess the wear of the brake pads and its effect on the stress-strain state in order to guarantee the railway traffic safety during the relevant theoretical and practical studies. 2019-01-01T00:00:00Z