No abstract

One of the most important indicators of the quality of transport services to the population is the coefficient of the use of rolling stock capacity. This parameter directly affects economic efficiency of the transport organization: the carrier is concerned with the highest value of the capacity utilization coefficient. The passenger, on the contrary, prefers service without overcrowding of the rolling stock. In practice, the average coefficient of dynamic capacity utilization for the relevant period is calculated, which is used in determining passenger fares, the analysis of the performed traffic in terms of available reserves of carrying capacity, planning of the transportation process. The paper considers the methodology of calculating the maximum permissible value of the coefficient of capacity utilization, on the basis of ensuring the normal occupancy of the cabin throughout the routes during the entire period of transport movement. The solution to determine the maximum permissible occupancy of rolling stock at work on regular city routes is offered, the task on the basis of analysis of dependence of the factor of use of capacity from parameters of passenger flows, average time of work of rolling stock on the route and non-uniformity of speed of communication during the work of passenger transport is offered. It was proposed to estimate the fluctuations of the communication speed during the movement of urban passenger transport by means of the coefficient of non-uniformity of the communication speed. It is established that the coefficient of using the rolling stock capacity depends substantially on the parameters of passenger flows, the average operating time of the rolling stock on the route and the unevenness of the speed of communication during the period of transport operation.The obtained dependencies make it possible to calculate the maximum permissible value of the capacity factor, taking into account the parameters of the planned transport process. Depending on the operating conditions, the capacity utilization factor varies within a significant range from 0.2 to 0.4.

Introduction. The ways of increasing the reliability of road construction machinery operation are considered. As a result, an option is proposed to replace the used 09Г2С steel with 30MnB5 boron steel. Using the example of a motor grader blade, the force effects on this working body of the road construction machinery are analyzed. In order to increase the level of physical and mechanical characteristics of 09Г2С and 30MnB5 steels, they are additionally exposed to thermo cyclic treatment. The experimental studies about the influence of this type thermal action on the structure and properties of steels are described. The comparative analysis of the obtained characteristics allows making a conclusion about the possibility of the considered replacement.Materials and methods. Through the metallographic analysis the influence of the number of thermal effects cycles on the grain size of steel is investigated. Alongside a set of physical and mechanical characteristics of these steels was determined at various stages of the thermo cyclic treatment.Results. It was determined that an increasing the level of physical and mechanical characteristics of the studied steels is possible through the use of thermo cyclic treatment. This is achieved by producing a fine-grained metal structure with a higher strength. The dependence of the tensile strength and yield strength of the steels under investigation on the number of cycles of thermal action is considered. Some correlation relationships were selected to describe these dependencies. The relationship between the yield stress and ultimate strength of 09Г2С and 30MnB5 steels and the grain size is considered. All investigated dependencies are presented in graphical form.Discussion and conclusion. Based on a comparative analysis of the complex of physical and mechanical characteristics, the conclusion about the possibility of replacing 09Г2С steel with 30MnB5 steel was made.

Changes in road legislation and trucking regulations have led to the need to take into account the maximum axle loads that arise during road transport. In particular, this task is relevant when transporting bulk cargo because when braking or accelerating trucks (road trains), when driving on a longitudinal gradient, or when driving on curves, there can be a displacement of part of the cargo relative to the axles of the vehicle. In article results of experimental research of displacements of loose cargo (gravel, crushed stone) at transportations and their influence on change of axle loadings of cargo vehicles are resulted. During the research the level of loose cargo in semitrailer truck-trailer before and after the experiment was measured, axle load weighing and full train weight weighing was made, in addition video recording of loose cargo displacement was made. Conducting the analysis of experimental data of axial weighing we found out that during transportation of loose cargo its redistribution inside semi-trailer takes place, and it in its turn leads to change of axle loads of road-train. The axle load variations were outside the measurement error range of 1.4 to 4.9%. A further proof of the shifting of the bulk load in the semi-trailer was the video recording of the load in transit. The analysis of the videos showed that both crushed stone and gravel shifted in the semitrailer when the vehicle was moving at high speed. As a result of this work, an experimental confirmation of the fact that the bulk cargo is shifted relative to the sides of the semi-trailer during braking and this shift leads to changes in the axle loads of trucks was obtained.

In the operation of aerial ropeways, the system of load-bearing and running skyline system, which provides the ability to move passengers or transported cargo between the endpoints of the route, experiences a high level of loading from a variety of operational loads and environmental influences. Those loads and influences form the rope system tension that is variable along the rope route and has a decisive influence on the main technical and economic parameters of mobile ropeways, and thus determine the concrete areas of their effective and inexpedient or unacceptable use. This article presents an engineering method of building the diagrams of the tension of the fixed and non-stationary operation modes of a mobile ropeway. The presented calculation dependences allow to determine the rope pull forces at the characteristic points along their length and the calculation dependences for determining the rope resistance forces at the characteristic portions of the mobile ropeway route. This method can be used both for the estimation of rope system loading based on a great number of factors that characterize operational loads, terrain and transported cargo parameters, and for the analysis of orientation and importance of variation of the stated factors and main design parameters of the main technological equipment of mobile transportation-transporting rope complexes. Also, the analysis results of influence of variation of a number of significant quantitative parameters on the change of nonlinear ropes’ pulling forces are presented.