scholarly journals Analysis of dynamic loads on the cars of a high-speed motor-car train with a passive safety system in its collision with a freight car

2020 ◽  
Vol 2020 (3) ◽  
pp. 79-90
Author(s):  
M.B. Sobolevska ◽  
◽  
N.Yu. Naumenko ◽  
D.V. Horobets ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
Dynamic Loads ◽  
Passive Safety ◽  
Level Energy ◽  
Energy Capacity ◽  
Passive Protection ◽  
Front End ◽  
Freight Car ◽  
Energy Absorbing

The performance characteristics of the cars of a modern home high-speed motor-car train must meet Ukrainian State Standards DSTU EN 12663 and DSTU EN 15227 now in force in Ukraine, which regulate its crashworthiness and passive safety in emergency collisions. An integral part of new cars must be passive safety systems (PSSs) with energy-absorbing devices (EADs), which save the lives of the pasengers and the train crew and reduce car damage in a collision with an obstacle. The aim of this paper is to evaluate dynamic loads on the cars of PSS-equipeed motor-car train in its collision with a freight car according to Scenario 2 of DSTU EN 15227. The scientific novelty of the paper is a mathematical model for the study of a collision of a motor-car train with a freight car based on the authors’ model of a collision of identical motor-car trains (Scenario 1 of DSTU EN 15227) with account for the force characteristic of head car – freight car interaction in an emergency. The proposed mathematical model allows one to obtain the average values of the car accelerations and plastic deformations to compare them with their admissible values according to DSTU EN 15227. The paper presents the results of a study of dynamic loads on the cars of a PSS-equipped motor-car train in its collision at 36 km/h with a 80 t freight car for a reference train with a 80 head car and four intermediate cars of mass 50 t, which is the mass of the majority of cars on the 1,435 mm European railways, and 64 t, which is the typical mass of inremediate cars used in the 1,520 mm Ukrainian railways. The following protective devices developed at the Institute of Technical mechanics of the National Academy of Sciences of Ukraine and the State Space Agenccy of Ukraine are proposed for passive protection: EAD 1 devices of energy capacity 0.95 MJ to be mounted at the coupler level at the head car front end, EAD 2 devices of energy capacity 0.25 MJ and EAD 3 devices of energy capacity 0.3 MJ to be mouned at the coupler level at the head car rear end and at the ends of passenger cars of mass 50 t and 64 t, respectively, and EAD UL upper-level energy-absorbing devices of energy capacity of 0.12 MJ to be mounted at the head car front end under the window. It is shown that by the criteria of DSTU EN 15227 for a train with 50 t intermediate cars it is advisable to use the passive protection according to Scenario 1 (the front end of the head car is equipped wuth two EAD 1 and two EAD UL devices, its rear end is equipped with two EAD 2 devices, and the intermediate cars are equipeed with two EAD 2 devices at the front and at the rear), while for a train with 64 t intermediate cars it is advisable to use the passive protection according to Scebario 2 (the front end of the head car is equipped wuth two EAD 1 and two EAD UL devices, its rear end is equipped with two EAD 3 devices, and the intermediate cars are equipeed with two EAD 3 devices at the front and at the rear). The proposed mathematical model and the results obtained may be used in designing head and intermediate cars for a home motor-car passenger train in accordance with the DSTU EN 15227 requirements.

scholarly journals Determination of the force characteristic of head car’s passive safety system – large road vehicle interaction in a collision

2021 ◽  
Vol 2021 (4) ◽  
pp. 118-128
Author(s):  
M.B. Sobolevska ◽  
◽  
D.V. Horobets ◽  
S.A. Syrota ◽  
◽  
...  
Keyword(s):  
High Speed ◽  
Passive Safety ◽  
Force Characteristic ◽  
Front Part ◽  
Road Vehicle ◽  
Passive Protection ◽  
Upper Level ◽  
Energy Absorbing ◽  
The Impact ◽  
Force Characteristics

One of the priorities of the National Economic Strategy of Ukraine for the Period up to 2030 is the development of the transport sector, in particular railway vehicle renewal, the introduction of high-speed railway passenger transport, and railway traffic safety improvement. The home motor-car trains must be renewed in compliance with new home standards harmonized with European ones, among which one should mention the Ukrainian State Standard DSTU EN 15227, which specifies the passive safety of a passenger train in its emergency collisions with different obstacles. New car designs must provide not only effective up-to-date braking systems to prevent emergency collisions, but also passive safety systems with energy-absorbing devices. The main purpose of these devices is to reduce the longitudinal forces in the intercar connections and the car accelerations to an acceptable level for the three collision scenarios specified in the DSTU EN 15227. The Department of Statistical Dynamics and Multidimensional Mechanical Systems Dynamics, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, developed a passive protection concept for home high-speed passenger trains in emergency collisions by the DSTU EN 15227 scenarios, proposals on the passive protection of a motor-car train head car, and honeycomb designs of lower- and upper-level energy-absorbing devices (EAD 1 and UL EAD, respectively), which are integrated into the head car front part and serve to damp the major part of the impact energy in front collisions with obstacles. This paper considers DSTU EN 15227 Scenario 3: a collision of a reference motor-car train at a speed of 110 km/h at a railway crossing with a large 15 t road vehicle, which is simulated as a large-size deformable obstacle (LSDO). The aim of the paper is to determine the force characteristic of the interaction of energy-absorbing devices mounted on the head car front part with a large road vehicle in a collision to assess the compliance of the proposed passive protection with the normative requirements. Finite-element models were constructed to analyze the plastic deformation of the elements of the EAD 1 – LSDO, UL EAD – LSDO, and EAD 1 – UL EAD –LSDO systems in a collision with account for geometric and physical nonlinearities, steel dynamic hardening as a function of the impact speed, and varying contact interaction between the elements of the systems considered. The studies conducted made it possible to determine the force characteristics of energy-absorbing device – obstacle interaction and the total characteristic of the contact force between two lower-level devices and two upper-level ones as a function of the obstacle center of mass displacement in a collision. The proposed mathematical models and the calculated force characteristics may be used in the study of the dynamics of a reference motor-car train – large road vehicle collision with the aim to assess the compliance of the passive protection of the home head car under design with the DSTU EN 15227 requirements.

scholarly journals Increasing the safery of railway passenger and freight traffic

2021 ◽  
Vol 2021 (2) ◽  
pp. 78-90
Author(s):  
O.M. Markova ◽  
◽  
M.V. Sobolevska ◽  
T.F. Mokrii ◽  
D.V. Horobets ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Safety System ◽  
Passive Safety ◽  
Transport Sector ◽  
Force Characteristic ◽  
Passive Protection ◽  
Railway Traffic ◽  
Freight Traffic ◽  
Passive Safety System ◽  
Starting Point

In 2020, the Ukrainian Government conducted an audit of the Ukrainian economy for nearly 30 years of independence and decided on the vectors of economic development aimed at European and Euro-Atlantic integration. The audit of the Ukrainian railways showed that most of the railway assets are critically worn. The audit and the vectors became a starting point for the development of the National Economic Strategy of Ukraine up to 2030, which was approved on March 3, 2021. One of the priorities of this strategy is the development of the transport sector by a succession of steps, including railway track and vehicle renewal, the introduction of high-speed passenger transport, and increasing railway traffic safety and environment safety on the Urrainian railways. The aim of this paper is to work out recommendations on increasing the safety of passenger and freight traffic in Ukraine. The paper generalizes the experience gained over the years of Ukrainian independence in the fundamental and applied transport-oriented reseach conducted at the Department of Sttistical Dynamics and Multidimensional Mechanical Systems, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine. This experience may be useful in the implementation of the above steps on the way to the sustainable development of the Ukrainian railway transport. In the paper, emphasis is on new investigations into the passive propection of the cars of a motor car train in emergency collisions whose scenarios are specified by Ukrainian State Standard DSTU EN 15227. Based on a mathematical model of a collision of identical motor car trains, a mathematical model was developed to simulate a collision of a motor car train with a large vehicle at a crossing with account for a specified force characteristic of interaction of the leading car equipped with a passive safety system with a deformable obstacle. The model developed was used in analyzing dynamic loads on the cars of a motor car train with a passive safety system in its collision at 110 km/h with a 15 t large vehicle at a railway crossing. With consideration for the results of previous investigations into the dynamics of emergency collisions of a motor car train with an identical train and a fright car, recommendations were worked out on the passive protection of a home-made leading car in accordance with the requirements of normative documents. The proposed mathematical models and designs of energy-absorbing devices, the research results, and the practical recommendations worked out may be used in designing new motor car train vehicles for the Ukrainian railways in accordance with the DSTU EN 15227 requirements for passive protection in emergency collisions.

A Method for Measuring the Dynamic Behaviour of the Rome-Florence High-Speed Track Switch Manoeuvring System

1992 ◽  
Vol 206 (2) ◽  
pp. 107-116 ◽  
Author(s):  
A Bracciali ◽  
M Biagiotti
Keyword(s):  
Mathematical Model ◽  
Working Conditions ◽  
High Speed ◽  
Test Bench ◽  
Dynamic Behaviour ◽  
Dynamic Loads ◽  
Test Procedures ◽  
Connection System ◽  
High Speed Trains ◽  
Physical Tests

A mathematical model of the dynamic loads induced at a switch machine and at the rails by the passing of a train was formulated and validated by physical tests. Attention was focused specifically on the switch machine itself and therefore the data gathered refers strictly to the attachment elements of the switch machine to the track and locally the track in the area of attachment. The research is part of a series of projects that aim to establish the factors that must be considered during the design of a switch machine. An accurate mathematical model of the connection elements between the track and the switch machine is helpful, especially in this period of widespread adoption of high-speed trains and the new working conditions that this imposes, in order to ascertain the characteristics of the accelerations transmitted to the switch machine and, as a consequence, to design the connection system of the machine to the track, based on these criteria. The data acquired can also be used for the construction of a realistic test bench to further improve test procedures. The pursuit of this project is a fundamental step in understanding the factors involved in the design of a switch machine.

scholarly journals Estimation of dynamic loads on a reference train with a passive safety system in its collisions with an identical train and a freight car

2017 ◽  
Vol 2017 (3) ◽  
pp. 72-83 ◽  
Author(s):  
N.Yu. Naumenko ◽  
◽  
M.B. Sobolevskaya ◽  
I.Yu. Khizha ◽  
◽  
...  
Keyword(s):  
Safety System ◽  
Dynamic Loads ◽  
Passive Safety ◽  
Passive Safety System ◽  
Freight Car

scholarly journals SIMULATION OF EMERGENCY COLLISION OF A MAGNETIC LEVITATION TRAIN WITH AN OBSTACLE

2015 ◽  
Vol 1 (1) ◽  
pp. 99-111
Author(s):  
Eldar M RYAZANOV ◽  
Alexander Ed PAVLYUKOV
Keyword(s):  
Traffic Safety ◽  
High Speed ◽  
Magnetic Levitation ◽  
Passive Safety ◽  
Rolling Stock ◽  
Work Effectiveness ◽  
Passive Safety Systems ◽  
Materials Used ◽  
Energy Absorbing ◽  
Safety Systems

In the last decades much attention has been focused on improving the passive safety of automobile, aviation, railway and shipbuilding vehicles by means of development of special energy-absorbing devices (EAD). The operation principle of such devices is to absorb the kinetic energy of the collision with the obstacle by means of the controlled irreversible deformation of its own design [1]. The article proposes to implement these devices and passive safety systems to assess their effectiveness. The solution of this issue was carried out by the authors' methods of numerical simulation of emergency collision of a rolling stock with an obstacle [2-4]. The article demonstrates the simulated emergency crash system of the passenger magnetic levitation train. It consists of a front and undercar crash-modules. The first is mounted on the end part of the head car of the train to absorb the collision energy with a large obstacle in case of an accident. The second is designed to reduce the consequences of collisions with obstacles of relatively small sizes, able to break the floor or damage undercar equipment at high speed. Various designs and materials used for manufacturing of EAD were theoretically investigated using the developed model of emergency collision. In the result the assessment of work effectiveness of the designed emergency crash-system in accordance with the existing regulatory requirements for traffic safety was carried out.

scholarly journals Passive Switched Capacitor RF Front Ends for Spectrum Sensing in Cognitive Radios

2014 ◽  
Vol 2014 ◽  
pp. 1-20
Author(s):  
Bodhisatwa Sadhu ◽  
Martin Sturm ◽  
Brian M. Sadler ◽  
Ramesh Harjani
Keyword(s):  
Spectrum Sensing ◽  
Circuit Design ◽  
Software Defined Radio ◽  
High Speed ◽  
Cognitive Radios ◽  
Optimization Techniques ◽  
Switched Capacitor ◽  
Rf Receiver ◽  
Front End ◽  
5 Ghz

This paper explores passive switched capacitor based RF receiver front ends for spectrum sensing. Wideband spectrum sensors remain the most challenging block in the software defined radio hardware design. The use of passive switched capacitors provides a very low power signal conditioning front end that enables parallel digitization and software control and cognitive capabilities in the digital domain. In this paper, existing architectures are reviewed followed by a discussion of high speed passive switched capacitor designs. A passive analog FFT front end design is presented as an example analog conditioning circuit. Design methodology, modeling, and optimization techniques are outlined. Measurements are presented demonstrating a 5 GHz broadband front end that consumes only 4 mW power.

Prediction of Surface Roughness in Compressed Air Jet Assisted High Speed End Milling of Silicon Using Diamond Coated Tools

2012 ◽  
Vol 576 ◽  
pp. 41-45
Author(s):  
A.K.M. Nurul Amin ◽  
M.A. Mahmud ◽  
M.D. Arif
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Surface Finish ◽  
High Speed ◽  
End Milling ◽  
Silicon Wafers ◽  
Compressed Air ◽  
Machining Parameters ◽  
High Quality ◽  
Ductile Mode

The majority of semiconductor devices are made up of silicon wafers. Manufacturing of high-quality silicon wafers includes numerous machining processes, including end milling. In order to end mill silicon to a nano-meteric surface finish, it is crucial to determine the effect of machining parameters, which influence the machining transition from brittle to ductile mode. Thus, this paper presents a novel experimental technique to study the effects of machining parameters in high speed end milling of silicon. The application of compressed air, in order to blow away the chips formed, is also investigated. The machining parameters’ ranges which facilitate the transition from brittle to ductile mode cutting as well as enable the attainment of high quality surface finish and integrity are identified. Mathematical model of the response parameter, the average surface roughness (Ra) is subsequently developed using RSM in terms of the machining parameters. The model was determined, by Analysis of Variance (ANOVA), to have a confidence level of 95%. The experimental results show that the developed mathematical model can effectively describe the performance indicators within the controlled limits of the factors that are being considered.

Research on the Performance Simulation of the Transmission System of Loader with Secondary Regulating Technique

2010 ◽  
Vol 426-427 ◽  
pp. 299-302
Author(s):  
Fa Ye Zang
Keyword(s):  
Mathematical Model ◽  
Fuzzy Control ◽  
Energy Saving ◽  
High Speed ◽  
Transmission System ◽  
Performance Simulation ◽  
Constant Torque ◽  
Braking Torque ◽  
The Mathematical Model ◽  
Inertial Energy

Based on deeply analyzing the working principles and energy-saving theory of loader secondary regulating transmission system, regenerating the transmission system’s inertial energy by controlling constant torque was put forward. Considering large changes of the parameters of the transmission system and its non-linearity, a fuzzy control was adopted to control the transmission system, and the mathematical model of the system was established, then the simulations of the performance of the transmission system has been conducted. The conclusion was made that the inertial energy can be reclaimed and reused in the system by the application of the secondary regulation technology, and braking by controlling constant torque is stable, it can ensure the security of braking at high speed and also permits changing the efficiency of recovery by changing the braking torque. The system’s power has been reduced and energy saving has been achieved.

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