Currently, a significant number of units of specialized cars of 1520 mm gauge in Ukraine has a service life that exceeds that assigned by the manufacturer. At the same time, many years of experience ...in diagnosing and analyzing the operation of carts of these cars by specialized organizations, shows that their technical condition after long operation shows that the specified service life specified in the technical conditions in most cases far from the limit. This is largely due to the significant margin of safety, which is laid down in the design, and the peculiarities of the operation of a particular type of car. The paper considers the issues of assessing the operation of such cars on the example of the carriage of the weighing car, bogie model 18-102, and the carriage of the passenger car model KVZ-TsNII used in the track economy for transportation of workers. The average daily mileage of such cars is 60-70 percent less than the average mileage that is laid down when calculating the service life assigned by the manufacturer. The evaluation and methods of determining the strength of the frames of carriages of special cars are performed. Conclusions are made based on the results of the analysis of the strength of the carriages of special cars.
Purpose. To determine the basic dynamic characteristics of a standard Ukrainian boxcar with the Y25 bogie by means of the mathematic modelling of dynamic loads in the vertical plane and to compare ...them with the dynamic characteristics obtained for a boxcar with the 18100 bogie. It can be used for substantiation of application of the Y25 bogie as more promising, which can improve the operational efficiency of rail transportation and foster integration of the Ukrainian transport system into the European transportation complex. Methodology. The authors used the mathematical modelling of a boxcar with the Y25 bogie. The research was made in the vertical plane. It was taken into account that an empty car passed over a joint irregularity. The research was made for an 11217boxcar as a predominant type to be used. The authors studied the motion of a car on the 18100 and Y25 bogies. The basic dynamic characteristics were determined for a boxcar with the nominal (design) dimensions of the carrying elements and a boxcar with the actual dimensions (after a long service life) on the basis of the field tests. The differential equations were solved by theRungeKutta method in MathCad software suite. The initial displacements and the speeds were taken equal to zero. The following dynamic characteristics of a boxcar were obtained: acceleration of the body in the center of mass, acceleration of the body in the areas of support on the bogies, forces in the spring suspension of the bogie, and dynamic coefficients of the bogies. Findings. The theoretical research showed that the basic dynamic characteristics of a boxcar with the nominal dimensions were improved by 3851% in comparison to a similar one with the 18100 bogie, and for a boxcar with the actual dimensions the dynamic characteristics were improved by 4350%. Originality. The authors substantiated the application of the Y25 bogie for a standard Ukrainian boxcar with the nominal and actual dimensions of the carrying elements by means of the mathematical modelling of the dynamic loads in the vertical plane. Practical value. Due to lower dynamic loads on the carrying structures of freight cars with the Y25 bogie, it is possible to improve the dynamic characteristics of the structures under the operational modes, to increase the fatigue strength and the operational resource, to decrease the total repair and maintenance costs, to ensure better security and reliability of freight transportation through lower loads on both carrying structures and lashing devices, to increase the speed of freight delivery thanks to better dynamic characteristics of cars, to improve the traffic security, and so on.
Purpose. To present the results on the possibility of increasing the efficiency of the use of the operated fleet of freight wagons by creating conceptual solutions for the manufacture of their ...component load-bearing systems from composites. Methodology. To increase the efficiency of using the operating fleet of freight wagons measures are offered on the development of conceptual solutions for the manufacture of their components load-bearing systems made of composites. In order to determine the possibility of service life of the basic structures of the freight wagons, the methodology given in the works by A. V. Afanasyev was used. To study the dynamic loading of the freight wagon with the actual dimensions of the constituent elements, a calculation was made. At the same time, a mathematical model was used, formed by Professor G. I. Bogomaz, taking into account its adaptation to the determination of the dynamic loading. The vertical loading of the load-bearing structure of the freight wagon was also investigated. In this regard, a mathematical model formed by Professor Yu. V. Demin was used. The accelerations obtained in the simulation of dynamic loading were taken into account when calculating the strength of the basic structure of the freight wagon. Findings. It has been established that the design service life of the load-bearing structure of a freight wagon is at least 50 years. The results of determining the longitudinal loading of the basic structures of the freight wagon established that the acceleration acting on it is 37.7 m/s2, and with the vertical one – 5.5 m/s2. The strength calculation of the basic structure of a freight wagon showed that the maximum equivalent stresses are recorded in the zone of interaction of the center beam with the pivot and amount to 333.4 MPa, i.e. do not exceed the permissible values. Originality. The feasibility of manufacturing component load-carrying systems of freight wagons from composites is substantiated. Practical value. The research carried out will contribute to an increase in the efficiency of the use of railway transport, the transportation process through international transport corridors, as well as the creation of developments in the design of multifunctional car structures.
Purpose. Creation and substantiation of the measures for adopting the supporting structure of the multipurpose semi-car to carry cargoes that need weather protection. Methodology. For the adaptation ...of supporting constructions of semi-cars to carriage of cargoes that need weather protection, it was proposed to apply a removable roof manufactured from composites. As the application of a removable roof enlarges the volume of the container of the semi-car, the authors defined the load on its construction with the help of mathematical modeling. The authors see semi-car as a system which includes three components – a supporting construction having a roof with two carts. The Runge-Kutta method was used to calculate the main dynamic parameters of the semi-car. These defined dynamic parameters were accounted during calculation of the strength of the dismountable roof. Graphic spatial modeling of a semi-car with a dismountable roof was performed in the SolidWorks software kit. The calculation of solidity is implemented by the method of ultimate elements using the SolidWorks Simulation program kit. The original frequencies and forms of vibrations of the supporting construction of the semi-car are performed in this research. Findings. The outcomes of a mathematical model of the dynamic loading of the supporting construction of the semi-car having a dismountable roof set that the obtained dynamic parameters are not higher than the allowable values. The acceleration of the semi-car supporting construction in the gravity center made approximately 4.5 m/s2. The vertical dynamic ratio amounts to 0.53. The car motion is evaluated as “excellent”. It was found that when the vertical load acts on the dismountable roof, the maximum tension emerging inside is 173.2 MPa. When concentrated load affects the dismountable roof, the biggest tensions are focused on the zones of its attachment to the upper strapping of the casing, and makes 205.7 MPa. It can be seen from the modal analysis that the first original frequency of the semi-car casing is equal to 9.6 Hz, which is more than the allowable value – 8 Hz. Originality. Models for determining the loading of the supporting construction of the semi-car having a dismountable roof from composites within the general modes of loading operation are given in this study. Practical value. The study results allow expanding the applicability of semi-cars by adapting them to the carriage of cargoes, which need protection from weather effects and can increase the performance of railroad carriage.
Purpose. To substantiate the improvement of the load-bearing element of the wagon-platform for the possibility of transporting bulk cargoes. Methodology. In order to be able to transport bulk cargo ...on the wagon-platform, it is proposed to install a composite boiler module on it. In order to determine the dynamic load of the improved load-bearing structure of the wagon-platform, mathematical modeling was performed. The mathematical model formed by professor Bohomaz H.I. was used. However, within the framework of the research this model was refined to determine the load of the wagon-platform of the proposed design. The solution of the system of differential equations is carried out in the MathCad software package. To do this, the mathematical model was reduced to the normal Cauchy form, and then integrated by the Runge-Kutta method. The obtained acceleration is taken into account when calculating the strength of the advanced load-bearing structure of the wagon-platform. The calculation is performed in the SolidWorks Simulation software package, which implements the finite element method. Also, within the research the modal analysis of a load-bearing structure of the wagon-platform is carried out. Findings. Based on the calculations, it is established that the acceleration acting on the load-bearing structure of the wagon-platform car is 0.38 g, i.e. it is within acceptable limits. The results of the calculation of the strength of the improved design of the wagon-platform showed that the maximum equivalent stresses occur in the area of interaction of the spine beam frame with the pivot and is about 340 MPa, the maximum displacement made 8.6 mm. That is, the obtained stresses do not exceed the yield strength of the structural material. The results of the modal analysis showed that the values of the natural frequencies of oscillations are within acceptable limits, because the first natural frequency has a value greater than 8 Hz. Originality. The scientific substantiation of improvement of a load-bearing structure of a universal wagon-platform to transportations of bulk cargoes is carried out. Practical value. The conducted research will promote increase in efficiency of operation of railway transport and creation of developments concerning planning of innovative designs of a rolling stock.
The article presents the study results of the dynamic loading of a flat wagon with a lower gravity center.The authors built a mathematical model that takes into account displacements of a flat wagon ...loaded with an anti-aircraft installation firing in motion. The solution of the differential equations of motion is carried out by using the Runge-Kutta method. The maximum vertical acceleration was about 5 m/sec2 and almost independent of the fire angle. The horizontal acceleration was about 37 m/sec2. The acceleration values obtained did not exceed the normative ones. The study defined the natural oscillation frequencies for the frame of a flat wagon with lower gravity center. It was established that the critical oscillation frequencies were within the admissible values. The results of the work will contribute to the creation of recommendations on the transportation of military equipment on wagons and the possibility of conducting military operations from them.
The study deals with research through mathematic modeling of the dynamic loading on the carrying structure of a flat wagon in transportation of military equipment conducting fire. A 13-401 flat wagon ...loaded with a tank with combat load of 55 tons was taken as the prototype. The mathematical model was solved in MathCad software. It was established that the maximum acceleration on the carrying structure of a flat wagon in the horizontal plane was about 40 m/sec2, and in the vertical plane - about 10 m/sec2. The values obtained were considered in strength calculation for a flat wagon. The calculation was made using the finite element method in CosmosWorks software. It was established that the maximum equivalent stresses in the carrying structure of a flat wagon exceeded the admissible values twice. The results of the study will encourage engineers to design carrying structures of flat wagons intended for transporting military equipment firing in motion
The dynamic loading of the flat wagon supporting structure during the military equipment transportation and conducting fire from it is investigated. A flat wagon model 13-401 by the construction of ...Dniprodzerzhirsk Car Building Plant (Ukraine) was chosen as a prototype. It was taken into account that the flat wagon was loaded with two anti-aircraft systems of muzzle energy of 89 kJ. The accelerations acting on the supporting structure of the flat wagon are determined using mathematical simulation. At the same time, it was taken into account that a simultaneous shot from two anti-aircraft systems is carried out. The solution of the mathematical model was carried out in the MathCad software. It has been found that the longitudinal accelerations of the flat wagon supporting structure were about 36 m/s2, and the vertical ones were about 5 m/s2. The obtained accelerations were taken into account when determining the equilibrium stability of the flat wagon, considering the conducting fire. The stability factor in this case was about 9. The calculation results of the strength of the flat wagon supporting structure are presented. The calculation was carried out in a quasi-static state. It has been established that the maximum equivalent stresses occur in the areas of frontal stops of the automatic coupling and amount to about 300 MPa. The results of the research will contribute to the creation of innovative flat wagon load-bearing structures for the military equipment transportation with the possibility of firing while moving.
Purpose. To study the feasibility of using the fillers for the gondola car bearing structure components. This makes it possible to reduce both damage to the gondola car bearing structure components ...during operating modes of loading and the cost of unscheduled repairs. In addition, it can improve the efficiency of railway transport operation. Methodology. In order to substantiate the use of aluminium foam as a filler for the gondola car bearing structure components with a closed box-section, a computational modeling of loading under the most unfavorable operating mode, such as shunting collision, has been performed. Gondola car 12-757 model built at PJSC Kryukovsky Railway Car Building Works is chosen as a prototype. The calculation is performed using the finite element method implemented in the SolidWorks Simulation (CosmosWorks) software package. The fatigue strength and natural vibration frequencies of the gondola car bearing structure with a filler of its components have been calculated. The natural vibration frequencies of the bearing structure of the gondola car are calculated. The design service life of the gondola car bearing structure has been determined. The main indicators of the gondola car bearing structure dynamics have been studied. The calculation is made in a plane coordinate system. In this case, the mathematical model is solved by the Runge-Kutta method. Findings. The results of the conducted research have revealed that the use of aluminium foam as a filler for the gondola car bearing structure components contributes to reduction of their load-bearing capacity from 12 to 47% compared to the prototype wagon. Originality. The expediency of using aluminium foam as a filler of the gondola car bearing structure components by modeling its load-bearing capacity under the most unfavorable operating conditions has been scientifically substantiated. Practical value. By reducing the loading on the gondola car bearing structure, using aluminium foam as filler for its components, it is possible to increase fatigue strength, reduce the amount of damages, and, consequently, the cost of unscheduled repairs of the wagon. The conducted research can contribute to the creation of recommendations for developing the innovative rolling stock designs with improved technical-and-economic, as well as operational performance.
To formalize logistic systems and technologies concerning the management of cargo delivery in terms of metallurgical production taking into consideration interaction between motor transport and ...railway transport. It is required to develop a logistic technology to manage transport generalizing efficiency indices and making it possible to optimize functioning of general transportation system of an enterprise. System analysis and logistic approach have been used. Transportation system of an enterprise has been analyzed from the viewpoint of logistics. The analysis makes it possible to integrate efficiency indices of functioning of certain subsystems of the general micrologistic system. Objective function and general model of transportation system optimization have been determined. Logistic technology providing optimization of the parameters of transportation system functioning according to general logistic criterion has been represented. Micrologistic systems have been singled out; tendencies to control the delivery aimed at providing functional efficiency of transportation system of an enterprise have been determined. Parameters and factors determining the parameters of transportation efficiency to the fullest extent being the basis of developing logistic transportation systems of enterprises have been identified. A system to control enterprise transport has been formalized from the viewpoint of a system approach and logistic technology providing high-efficiency transportation has been determined. Management efficiency is estimated according to the logistic criterion involving all expenses connected with cargo delivery. A system of managerial decision-making has been developed. The system is based upon logistic technology optimizing functional parameters of the enterprise transport.
PDF
