1* СКТБ МСУБ, Днепропетровский национальный университет железнодорожного транспорта имени академика В. Лазаряна, ул. Лазаряна, 2, Днепропетровск, Украина, 49010, тел. +38 (050) 214 14 НЕКОТОРЫЕ АСПЕКТЫ ОПРЕДЕЛЕНИЯ УСТОЙЧИВОСТИ ПОРОЖНИХ ВАГОНОВ ОТ ВЫЖИМАНИЯ ИХ ПРОДОЛЬНЫМИ СИЛАМИ В ГРУЗОВЫХ ПОЕЗДАХЦель. Несмотря на реализацию многочисленных программ по повышению безопасности движения поез-дов, проблема снижения сходов подвижного состава с рельсов по-прежнему является актуальной. Цель ис-следования -уточнить существующую методику определения коэффициента запаса устойчивости от выжи-мания продольными силами для обеспечения устойчивости вагонов при увеличении скоростей движения подвижного состава. Методика. Исследование проводилось методом математического моделирования на-груженности грузового вагона при движении с различными скоростями по прямым и кривым участкам пути. Результаты. Анализ полученных результатов показывает, что для всех выбранных для расчетов грузовых вагонов величины коэффициента запаса устойчивости от выжимания меньше, чем по нормативным форму-лам. Исправления, внесенные в формулу для определения коэффициента запаса устойчивости от выжимания продольными силами, позволят: 1) добиться повышения запаса устойчивости легковесных вагонов, исклю-чив их выжимание продольными силами во всем диапазоне допустимых скоростей движения грузовых по-ездов; 2) разработать и реализовать меры по предотвращению выжимания вагонов во всем диапазоне скоро-стей движения; 3) определить степень устойчивости порожнего вагона в голове, в середине и в хвосте гру-женого поезда; 4) предложить оптимальные схемы формирования смешанных поездов. Научная новизна. В исследовании приведен анализ существующих методик определения коэффициента запаса устойчивости вагонов в грузовых поездах от выжимания продольными силами, а также разработаны предложения по уточнению этих методик на стадии проектирования, постройки и в процессе эксплуатации. Практическая значимость. В данном исследовании уточняется существующая методика определения коэффициента запа-са устойчивости от выжимания продольными силами, а также оценивается влияние скорости движения под-вижного состава на величину этого коэффициента. Разработанные предложения по уточнению существую-щих методик определения коэффициента запаса устойчивости от выжимания вагонов продольными силами в поезде позволяют снизить количество сходов вагонов с рельсов. Это достигается за счет учета при расче-тах и проектировании важных параметров и характеристик, повышающих их устойчивость в рельсовой ко-лее, особенно при увеличении скоростей движения грузовых поездов.Ключевые слова: безопасность движения; нормы расчета; устойчивость вагонов от выжимания; скорость движения; коэффициент устойчивости 175
Development of a method for calculating the optimal mode of conducting a train in terms of energy saving meet the safety requirements and schedules. The method of calculation must solve the assigned tasks without significant time spent on the calculation. To implement this method of calculation was used a simplified model of the train as a controlled system. The existing mathematical and algorithmic methods for solving isoperimetric problems of finding the optimal solution in the presence of restrictions on resources were the information base for methodology development. Scientific works of domestic and foreign scientists, professional periodicals, materials of scientific and practical conferences, methodical and normative materials, currently in force on Ukrainian Railways. The results of these studies were used to create simulators on the basis of computer technology for the training of locomotive drivers. The scientific novelty of the proposed calculation method consists in applying the simplified calculations of the status of the train as a controlled system, without the use of differential equations of motion that allows to significantly increase the speed of the calculations. This, in turn, will solve the problems of finding optimal control in real time, taking into account changing conditions during the movement of the train. The practical significance of the obtained results is the use of such a calculation method that does not require significant time for its implementation and can be used as a subsystem of the on-board train control system capable of per-forming calculations taking into account changes in the current train situation.
The analytical study of the connection between the longitudinal force, acting on the light-weight car, lateral and vertical forces of interaction in the contact zone «wheel -rail» with the lift resistance factor value is to provide a simple relationships between them. Methodology. Research was conducted by the method of mathematical modeling of loading the freight car when driving at different speeds on straight and curved sections of a track. Findings. Even in the absence of «lift» accordingly the classical train stability theory, as the hinge-rod system, the presence of the longitudinal compressive forces may become a factor provoking cars derailment. The main reason of wheel climbing on rails is the combination of processes of dynamic interaction between the hunting vehicle and the track with simultaneous action of longitudinal compressive forces, and not the destabilization of train as a hingedrod system. To assess the impact of the longitudinal forces value on the lift resistance factor there are presented the calculation results for the empty gondola car motion, model No. 12-532, on 250 m radius curve with 150 mm rise and cross starting of car underframe relating to the track axis in 50 mm guiding section. The calculations were made in such a curve excluding the inertial forces from outstanding acceleration and taking into account the unbalanced acceleration with the permissible speed of 65 km/h. Originality. This study provides the technique of determining the lift resistance factor by longitudinal forces, which is somewhat different from the standard one, as well as evaluates impact of rolling stock speed on this factor. Practical value. The authors clarify the current method of determining the lift resistance factor by longitudinal forces and assess the impact of rolling stock speed on the value of this factor. From these studies one can conclude that because of cars hunting their lift is possible even when the train as hinge-rod system does not lose stability. The developed proposals allow reducing the number of car derailment by taking into account important parameters and characteristics during the process of calculation and design that increase their stability in the rail track especially in case of increased speed of freight trains.
Purpose. In the analytical research are considered: 1) relationships between the longitudinal force acting on the car in the train; 2) lateral and vertical forces of interaction in the contact zone «wheel – rail»; 3) dynamic indicators of cars with the magnitude of the car lift resistance factor; 4) obtaining of the dependencies between them. Methodology. The study was conducted by an analytical method assessing the sustainability of the freight car when driving at different speeds on the straight and curved track sections. Findings. In the process of studying the motion of the train, in the investigation of transport events, as well as during the training on the simulator operator, to assess the actions of the driver, the values of the longitudinal forces in the inter car connections are used. To calculate the longitudinal compressive forces, acting on the car, in which car lift resistance factor will be equal to the allowable value (critical force). To assess the impact on the value of the longitudinal force speed, coefficients of the vertical and horizontal dynamics, as well as the wind load on the side surface of the car body are the results of calculations of motion of the empty gondola car, model № 12-532 curve radius of 250 m with a rise of 150 mm and a transverse run of body of car frame relative to the track axis of the guide section 50 mm. Originality. In this study, the technique of determining the longitudinal compressive force was shown, that is somewhat different from the standard. So, as well as assessing the impact on it the speed of rolling coefficients of vertical and horizontal dynamics and wind load on the side surface of the car body. Practical value. The authors developed proposals on the enhancement of existing methods for determining the value of the longitudinal compressive forces acting on the car in which the safety value of the car lift resistance factor will be equal to the allowable value. It will evaluate the stability of each train car lift resistance factor directly during the simulation of its movement. The most effective use of this technique in the simulator designed to teach the drivers a safe way of driving trains and in the investigation of the causes of cars derailment.
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