scholarly journals LOADING ON THE CARRYING STRUCTURE OF A FLAT WAGON IN TRANSPORTATION OF MILITARY EQUIPMENT

2021 ◽  
pp. 6-19
Author(s):  
Oleksij Viktorovich Fomin ◽  
Glib Leonidovich Vatulia ◽  
Alyona Oleksandrivna Lovska
Keyword(s):  
Natural Frequencies ◽  
Computer Modelling ◽  
Vertical Plane ◽  
Dynamic Loads ◽  
Rolling Stock ◽  
Software Suite ◽  
Strategic Issues ◽  
Military Equipment ◽  
Longitudinal Plane ◽  
Mathcad Software

The article presents the results of determining the loads on the carrying structure of a flat wagon transported military equipment. The authors suggest that stable fixation of military equipment can be provided with special rings mounted on the flat wagon structure. The results of the strength calculation confirmed the efficiency of this solution. The study deals with the mathematical modelling of the dynamic loads on the carrying structure of a flat wagon with a military tank. The research was made for the plane coordinates. The following oscillations were taken into account: longitudinal plane oscillations, jumping oscillations and galloping oscillations. The differential equations were solved by the Runge–Kutta method in MathCad software suite. The maximum accelerations on the carrying structure of a flat wagon in the longitudinal plane were about 34 m/s2, and in the vertical plane were about 5.0 m/s2. Thus, these accelerations values were within the admissible ones.The study also presents the results of the computer modelling of the dynamic loads on the flat wagon. The calculations were made in SolidWorks Simulation (CosmosWorks) software suite with the finite element method. The study presents the distribution fields of the accelerations relative to the carrying structure of a flat wagon and the numerical values of these accelerations.The models of the dynamic loads on the carrying structure of a flat wagon were verified with an F-test. It has been found that the hypothesis on adequacy is not rejected.The study also included determination of the natural frequencies of the carrying structure of a flat wagon. It was found that the values of the natural frequencies were within the permissible values. This research will contribute to better operation efficiency of the rolling stock with consideration of some military-strategic issues, and will be of help for anyone concerned with development and research into innovative rolling stock structures

scholarly journals Determination of vertical dynamics for a standard Ukrainian boxcar with Y25 bogies

2020 ◽  
pp. 67-72
Author(s):  
O. V Fomin ◽  
A. O Lovska
Keyword(s):  
Mathematical Modelling ◽  
Dynamic Characteristics ◽  
Center Of Mass ◽  
Vertical Plane ◽  
Field Tests ◽  
The Body ◽  
Dynamic Loads ◽  
Theoretical Research ◽  
Predominant Type ◽  
Mathcad Software

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.

scholarly journals Determination of the Loading of a Flat Rack Container during Operating Modes

2021 ◽  
Vol 11 (16) ◽  
pp. 7623
Author(s):  
Oleksij Fomin ◽  
Juraj Gerlici ◽  
Glib Vatulia ◽  
Alyona Lovska ◽  
Kateryna Kravchenko
Keyword(s):  
Dry Friction ◽  
Vertical Plane ◽  
Dynamic Loads ◽  
Friction Forces ◽  
Operating Modes ◽  
Longitudinal Plane ◽  
Open Container ◽  
The Cross ◽  
Bearing Structure

This research deals with determination of the loading of an open container during operating modes. The special feature of this container is its convex walls. This engineering solution increases the useful capacity of a container by 8% in comparison to that of the prototype. The elastic elements in the bearing structure of a container were introduced to decrease the dynamic loads. The dynamic loads in the vertical plane were dumped by means of the dry friction forces between the components of the cross bearers of the container’s base. The dynamic loads in the longitudinal plane were dumped by means of the dry friction forces between the horizontal parts of fittings and fixed lashing components. This study presents the modelling of the dynamic loading of a container in a vertical plane. The dynamic loads of a container in the longitudinal plane were determined with a mathematical model. The authors determined the basic strength characteristics of the bearing structure of a container; and found that the maximum stresses to a container were about 200 MPa, concentrated near the front fittings. The maximum displacements were recorded in the cross bearers of the base and amounted to about 4 mm.

SIMP for Complex Structures

2016 ◽  
Vol 846 ◽  
pp. 535-540
Author(s):  
David J. Munk ◽  
David W. Boyd ◽  
Gareth A. Vio
Keyword(s):  
Natural Frequencies ◽  
Dynamic Loads ◽  
Topology Optimisation ◽  
Complex Structures ◽  
Structural Failure ◽  
Frequency Range ◽  
Aerodynamic Loading ◽  
Frequency Excitation ◽  
Wing Structure ◽  
Lifting Surfaces

Designing structures with frequency constraints is an important task in aerospace engineering. Aerodynamic loading, gust loading, and engine vibrations all impart dynamic loads upon an airframe. To avoid structural resonance and excessive vibration, the natural frequencies of the structure must be shifted away from the frequency range of any dynamic loads. Care must also be taken to ensure that the modal frequencies of a structure do not coalesce, which can lead to dramatic structural failure. So far in industry, no aircraft lifting surfaces are designed from the ground up with frequency optimisation as the primary goal. This paper will explore computational methods for achieving this task.This paper will present a topology optimisation algorithm employing the Solid Isotropic Microstructure with Penalisation (SIMP) method for the design of an optimal aircraft wing structure for rejection of frequency excitation.

Dynamics of an Array of Submersible Mussel Rafts in Waves and Current

2019 ◽  
Author(s):  
Tobias Dewhurst ◽  
Spencer T. Hallowell ◽  
Carter Newell
Keyword(s):  
Field Experiments ◽  
Natural Frequencies ◽  
Dynamic Loads ◽  
Full System ◽  
Mooring Lines ◽  
Element Analysis ◽  
Commercial Code ◽  
Scale Field ◽  
Waves And Currents ◽  
Corner Node

Abstract A three-by-three grid of submersible mussel rafts was analyzed using an experimentally validated dynamic numerical modeling approach. When submerged, the rafts’ pontoons are flooded, and they are held vertically by lines attached to surface floats and horizontally by a mooring grid. The rafts’ decreased waterplane area and increased inertia reduce the heave and pitch natural frequencies so that they are below the frequencies associated with the greatest wave energy. This has been found to significantly reduce the motion of the rafts compared to the surfaced configuration. The nine submersible rafts were anchored with 16 anchors and mooring lines. These mooring lines were connected to a grid of adjacent rectangular bays, with each corner (node) supported by a grid float. Each bay contains a raft connected to the submerged nodes of the grid by four bridle lines. The dynamics of the full system were modeled using a combined multibody and Finite Element Analysis (FEA) approach with dynamic loads computed using a modified Morison formulation. This model was implemented in the commercial code OrcaFlex. A similar model for a single submersible raft was previously validated with full-scale field experiments. The full dynamic system was simulated in the maximum expected waves and currents. Mean and maximum tensions in each grid line were quantified. Accelerations and velocities at the mussel rope attachment points were also examined, since these relate to mussel drop-off.

scholarly journals Indicators of the force interaction of the track and rolling stock when a freight car runs on long irregularities, taking into account the action of longitudinal forces

2021 ◽  
Vol 80 (6) ◽  
pp. 359-365
Author(s):  
E. A. Sidorova ◽  
V. O. Pevzner ◽  
A. I. Chechel’nitskiy
Keyword(s):  
Vertical Plane ◽  
Traction Force ◽  
Stability Margin ◽  
Railway Track ◽  
Rolling Stock ◽  
Vertical Force ◽  
Train Operation ◽  
Freight Car ◽  
Dynamics Stability ◽  
Universal Mechanism

Authors describe formation mechanism of long irregularities of the railway track and the importance of their elimination for the track facilities. Based on the results of freight train operation modeling on long irregularities in the traction mode, an analysis of the processes occurring during the motion of heavy trains along a track with such deviations was carried out, modeling was carried out on the basis of the “Universal Mechanism” software package. Based on the results of the calculation, interaction between the track and the rolling stock in the vertical plane was assessed in terms of the magnitude of the vertical force and coeffcients: dynamics, stability margin, Nadal, unloading (in percent) of axle springs of freight car springs. Article analizes the nature of the infuence of the irregularity slope on the decrease in the vertical force transmitted from the wheel to the rail and the change in the traction force on the dynamics of freight cars in the train and passing on long irregularities of the longitudinal profle through the indicators of the vertical force.

scholarly journals Dynamic Response Of Tower Structures

2015 ◽  
Vol 2 ◽  
pp. 85
Author(s):  
Liga Gaile ◽  
Ivars Radinsh
Keyword(s):  
Finite Element ◽  
Structural Changes ◽  
Natural Frequencies ◽  
Resonance Effect ◽  
Dynamic Loads ◽  
Mode Shapes ◽  
Finite Element Models ◽  
Dynamic Parameters ◽  
Vibration Level ◽  
Tower Structure

The present study focuses on the tower type structures response to the dynamic loads. The study analyzes the possible mode shapes regarding to tower structure. The estimation of mode shapes and their dependence from structural changes was made for an existing tower structure. To get an acceptable tower’s vibration level and avoid possibility of resonance effect from usual serviceability loads it was evaluated options to change natural frequencies of the structure. It is performed existing 36m high sightseeing tower dynamic analysis and proposed potential solutions to increase critical natural frequencies of the structure. In this study to obtain dynamic parameters of the sightseeing tower structure have been used finite element models and calculation techniques.

Influence of wear of traction transmission elements on life of drives of freight electric locomotives

2021 ◽  
pp. 61-63
Author(s):  
Alexander Petrovich Buynosov ◽  
◽  
Alexander Takhirovich Sharapov ◽  
Keyword(s):  
Direct Current ◽  
Gear Transmission ◽  
Dynamic Loads ◽  
Rolling Stock ◽  
Electric Locomotive ◽  
Bolted Connections ◽  
Structural Scheme ◽  
Traction Drive ◽  
High Dynamic ◽  
Gear Wheels

At operation of rolling stock all friction joints are supposed to wear especially heavy-loaded elements of freight electric locomotives. The paper analyses the distribution of failures according data of unplanned repairs and determines that a traction drive is a heavy-loaded element. The work shows its structural scheme and considers the influence of wear of traction transmission elements on drive life. The authors have processed and analysed spectrograms of a direct current freight electric locomotive. As a result, they have concluded that the reason of high dynamic loads on traction drive elements is the wear of gear wheels teeth that leads to appearance of cracks on body structures and to weakening of bolted connections. The authors propose a number of principled approaches to reduce the wear of gear transmission and body structures.

Theory of motion controllability of a wheel machine-tractor aggregate

2016 ◽  
Vol 3 (2) ◽  
pp. 3-10 ◽  
Author(s):  
V. Adamchuk ◽  
V. Bulgakov ◽  
V. Nadykto ◽  
I. Golovach
Keyword(s):  
Vertical Plane ◽  
Rectilinear Motion ◽  
Transport Mode ◽  
Longitudinal Plane ◽  
Theory Of Motion ◽  
Non Linear ◽  
Analytic Expressions ◽  
Computer Calculations ◽  
External Forces

Aim. To obtain analytically new dependencies, determining the indicator of motion controllability of a wheel machine-tractor aggregate, taking into consideration external forces, constructive and kinematic parameters of the aggregate while the latter moves in the transport mode. Methods. The methods of tractor and vehicle theories, theoretical mechanics, the theory of dynamic stability, and methods of numeric computer calculations. Results. A new theory of motion controllability of a wheel machine-tractor aggregate during its non-linear mo- tion along the surface of the soil at an angle to the horizontal was elaborated. The analytic expressions for the determination of the actual indicator of aggregate controllability, including force and constructive parameters of a machine-tractor aggregate, affecting this indicator in the longitudinal-vertical plane were made. The ana- lytic expressions were obtained for the transport mode of the aggregate movement. The conditions, in which cross slips of the directive wheels of the tractor with implements in the longitudinal plane were analytically considered for the fi rst time. The analytic expressions for the determination of the required indicator of the controllability of the machine-tractor aggregate in the longitudinal plane, excluding any possibility of a cross slip of the aggregate while turning its directive wheels at a certain angle, were defi ned. Conclusions. Computer calculations demonstrated that during the non-linear movement along the surface of the soil at an angle of 12 ° to the horizontal the wheel machine-tractor aggregate will be controllable only if the wheel turning angles for the tractor with implements do not exceed 9 ° . In case of the working motion of this aggregate along the slope, its controllability is preserved on condition that the turning angle of directive wheels does not exceed 11 ° . It was established that the controllability of the wheel machine-tractor aggregate is determined by the actual λ d and required λ о indicators of controllability, which take into consideration the values of the vertical load on the directive wheels of the power source, the possibility of their turn in the longitudinal plane, and the pull during the deviation from rectilinear motion when it moves along the surface at an angle to the horizontal.

Selected methods of measuring longitudinal stresses in continuous welded rail track

2018 ◽  
Vol 121 ◽  
pp. 373-380
Author(s):  
Łukasz Stolarczyk ◽  
Ewa Kardas-Cinal
Keyword(s):  
High Temperatures ◽  
Traffic Safety ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Summer Season ◽  
Dynamic Loads ◽  
Rolling Stock ◽  
Railway Traffic ◽  
Lateral Resistance ◽  
Continuous Welded Rail

High temperatures in the summer season lead to significant increase in compressive forces in railway rails. Significant stresses in rails caused by an increased temperature and dynamic loads from the rolling stock can reach values that can overcame the lateral resistance of the continuous welded rail (CWR) track. The result of overcoming the lateral resistance of the CWR track is the buckling phenomenon. The buckling of the track is a threat to railway traffic safety due to its sudden nature. The article presents various methods for measuring longitudinal forces in the CWR track, including the method using the Polish production extensometer. The use of this device for measurements of longitudinal forces has been accepted as optimal due to the ease of assembly, measurement accuracy and the ability to perform measurements without the need to stop trains. In the summary, the usefulness of the measurement method using the extensometer and its significance in the course of further research are evaluated.

scholarly journals Dynamics and Strength of Circular Tube Open Wagons with Aluminum Foam Filled Center Sills

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1915
Author(s):  
Oleksij Fomin ◽  
Mykola Gorbunov ◽  
Alyona Lovska ◽  
Juraj Gerlici ◽  
Kateryna Kravchenko
Keyword(s):  
Mathematical Modeling ◽  
Aluminum Foam ◽  
Natural Frequencies ◽  
Circular Tube ◽  
Dynamic Loads ◽  
Oscillation Modes ◽  
Absorbing Material ◽  
Foam Filled ◽  
Energy Absorbing ◽  
Tube Structure

The study deals with an application of aluminum foam as an energy-absorbing material for the carrying structure of a rail car. The material is particularly recommended for circular tube carrying structures. The authors conducted mathematical modeling of dynamic loads on the carrying structure of an open wagon that faces shunting impacts with consideration of the center sill filled with aluminum foam. It was established that the maximum accelerations on the carrying structure of an open wagon were 35.7 m/s2, which was 3.5% lower in comparison with those for a circular tube structure without a filler. The results obtained were proved by computer modeling. The strength of the carrying structure of an open wagon was also calculated. It was established that aluminum foam applied as a filler for the center sill decreased the maximum equivalent stresses in the carrying structure of an open wagon by about 5% and displacements by 12% in comparison with those involving the circular tube carrying structure of an open wagon without a filler. The natural frequencies and the oscillation modes of the carrying structure of an open wagon were defined. The designed models of the dynamic loading of the carrying structure of an open wagon were verified with an F-test.

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