scholarly journals Formation of a mathematical model of the dynamic loading of tractor suspension with semi-trailer

Author(s):  
Anatoliy Mamontov ◽  
Andriy Kozhushko ◽  
Oleksiy Rebrov
2019 ◽  
Vol 64 (1) ◽  
pp. 7-14
Author(s):  
Alexander V. Lagerev ◽  
Igor A. Lagerev

This research is aimed at developing a mathematical model and the methodology for computer simulation of hydraulically driven manipulators of mobile cranes having excessive backlashes in cylindrical joints. The authors proposed a structural design and considered the mechanism of reducing the additional impact load in the hinges by means of elastic damping of oscillatory processes. This method allows estimating the degree of influence of the backlash and stiffness of the elastic damper on the change in the quantitative characteristics of the dynamic loading of the manipulators metalwork and the motion parameters of the transported load. While in operation, the excessive backlashes may cause an increase in the level of dynamic loading of manipulators up to 2 times or more. However, the rational choice of the elastic dampers stiffness allows an effective solution to this problem to the point of complete elimination of the additional impact load.


Author(s):  
Vladimir Altuhov ◽  
Aleksey Boldyrev ◽  
Pavel Zhirov

The article is devoted to the study of the influence of dynamic loading on the characteristics of polymer elements of shock absorbers of the rolling stock of railways and to the description of the creation of a mathematical model of their work. The results of mathematical modeling are further used to solve problems of the longitudinal dynamics of rolling stock. In the study, the initial loading rate varied, the ambient temperature and the influence of the wear factor remained unchanged. For the operating speeds of a freight car, a mathematical model of the PMKP-110 draft gear was determined.


Author(s):  
A. O Lovska ◽  
O. V Fomin ◽  
A. V Rybin

Purpose. The work aims to investigate dynamic loading of the supporting structure of a gondola car with an elastic-viscous filler in the center sill by means of mathematical modeling. Methodology. Mathematical modeling of the dynamic loading of the supporting structure of a gondola car with a closed center sill filled with a filler with elastic-viscous properties has been carried out. The case of the highest load on the supporting structure of the gondola car in operation is taken into account – a shunting collision, taking into account the action of a load of 3.5 MN on the rear stop of the automatic coupler. To determine the dynamic loading of a gondola car, a mathematical model formed by prof. G. I. Bohomaz was used. However, within the framework of this study, the model was refined by adapting it to the determination of the dynamic loading of a gondola car. It also takes into account the friction forces arising between the center plates of the body and the center pivots of the bogies, as well as the properties of the energy-absorbing material. The solution of the mathematical model was carried out in the MathCad software package. In this case, the differential equations of motion were reduced to the Cauchy normal form, and then integrated using the Runge-Kutta method. Initial displacements and speeds are taken equal to zero. The calculation was carried out on the example of a universal gondola car model 12-757 built by Kriukivskyi Carriage Works PJSC (Kremenchug) on standard bogies 18-100. Findings. Accelerations are obtained as components of a dynamic load acting on a gondola car with a closed center sill structure filled with an elastic-viscous filler. It was found that with the stiffness of the center sill filler of 82 kN/m, as well as the viscous resistance coefficient of -120 kN∙s/m, the maximum accelerations of the gondola car supporting structure is about 37 m/s2 (0.37g). Originality. A mathematical model is proposed for determining the dynamic loading of a gondola car with a closed structure of a center sill filled with an elastic-viscous filler. The model makes it possible to obtain accelerations as the components of the dynamic loading acting on the supporting structure of the gondola car, taking into account the improvement measures during a shunting collision. Practical value. The results of the research will help to reduce the damage to the supporting structures of gondola cars in operation, reduce the cost of their maintenance, create developments in the design of innovative structures of rolling stock, as well as increase the efficiency of its operation.  


Author(s):  
Alexey A. Semenov

The paper deals with shallow orthotropic shells of double curvature, square in plan, under dynamic loading. Outlines the ratios of the mathematical model of deformation considering the geometric nonlinearity, transverse shear and orthotropy material. For the formation of the ODE system is used method of Kantorovich. The resulting system is solved by the method of Rosenbrock. It is shown the verification of the proposed method for isotropic shells. For several options orthotropic shells made of fiberglass and carbon fiber studied their stability and obtained values of critical loads.


Author(s):  
Н.Г. Серёгин ◽  
В.Г. Исаев

Описана конструкция экспериментальной установки для проведения сравнительных испытаний износостойкости различных пар трения конструкционных материалов. Представлены результаты сравнительных испытаний износостойкости двух пар трения при статическом нагружении и определена лучшая из них. Приведены результаты испытаний износостойкости лучшей пары трения при динамическом нагружении. Разработана математическая модель динамического изнашивания лучшей пары трения конструкционных материалов. The design of an experimental installation for conducting comparative tests of the wear resistance of various friction pairs of structural materials is described. The results of comparative tests of the wear resistance of two friction pairs under static loading are presented and the best of them is determined. The results of tests of the wear resistance of the best friction pair under dynamic loading are presented. A mathematical model of dynamic wear of the best friction pair of structural materials is developed.


Author(s):  
Д.А. Билалов ◽  
В.А. Оборин ◽  
О.Б. Наймарк ◽  
М.В. Нарыкова ◽  
А.Г. Кадомцев ◽  
...  

An experimental study of the influence of preliminary dynamic loading on the endurance limit of an AlMg6 alloy based on 109 cycles was carried out. It is shown that when loading to a strain of 10% with a strain rate of 103 s-1, the endurance limit decreases by 22%. A mathematical model is proposed that is able to adequately predict fatigue failure, including after preloading.


Author(s):  
B Jerman

A fatigue analysis of a structure is nowadays a common part of the design process. One of the fundamental pieces of information for ensuring the high quality of the analysis is details of the dynamic loading of the structure. This information can be provided by means of a simulation using an appropriate mathematical model. In this article, a new mathematical model of a slewing crane is presented on the basis of the experiences gained with a previously developed model. Only the slewing motion that produces the spatial oscillation of the payload is considered, as this motion has received less attention than the translation of the suspension point. The mathematical model takes into account the non-linear nature of the swinging motion for large angles and the non-linearity of the power transmission to ensure sufficient accuracy. The structure's elasticity and damping, the friction in the main bearing, and the air resistance were also taken into account. The angles of swinging of the payload and the dynamic forces acting on the steel structure of the crane during payload transport were obtained. Measurements on an actual model of a crane were carried out for the purpose of confirmation of the mathematical model. The comparison of the results was executed and a good greement between the predicted and the measured values was observed.


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