Anatoly Zhygalov1, Vadym Stupnytskyy2
1 “Promlizing Corporation”, 14, Vitebskij av., Mogilev, Belarus, E-mail: indliz@mail.ru
2 Department of Mechanical Engineering Technologies, Lviv Polytechnic National University,
12, S. Bandery Str., Lviv, Ukraine, E-mail: stupn@i.ua
INVESTIGATION OF THE CARBIDE-TIPPED TOOL WEAR
HARDENED BY METHOD OF AERODYNAMIC IMPACT
Received: December 8, 2017 / Revised: December 25, 2017 / Accepted: December 26, 2017
© Zhygalov A., Stupnytskyy V., 2017
Abstract. Theoretical calculations and experimental studies of the influence of wear on the cutting process and the precision parameters of machining by hard alloys during milling are described in the article. The method of aerodynamic hardening is designed to increase the durability of tools, which are heterogeneous compositions of tungsten carbides, titanium and tantalum with cobalt ligature operating under severe process conditions with varying impact loads. The effect of hardening by the ADH method is achieved due to the influence of sound waves on the structure of hard alloys. The results of imitation studies of the wear process in the DEFORM system are described.
Keywords: cutting tools, wear, wear rate, method of aerodynamic hardening, simulation modeling, stress, deformation.

Кількість посилань 14

Andriy Kuzyshyn1, Andriy Batig2
1 “Railway Transport Researches” Laboratory, Lviv Research Institute of Forensic Science,
12, Lypynskyi Str., Lviv, Ukraine, E-mail: kuzyshyn1993@gmail.com
2 “Railway Transport Researches” Laboratory, Lviv Research Institute of Forensic Science,
12, Lypynskyi Str., Lviv, Ukraine, E-mail: batigasha1992@gmail.com
EVALUATION OF DYNAMIC CHARACTERISTICS OF DPKR-2 DIESEL TRAIN ON STRAIGHT SECTIONS OF RAILWAY TRACK
Received: December 12, 2017 / Revised: December 25, 2017 / Accepted: December 26, 2017
© Kuzyshyn A., Batig A., 2017
Abstract. The increase in motion speed of the trains moving along certain routs changes the operational conditions and interaction of the rolling stock and the track, and requires the solution of important issues related to the specifications of their maintenance, since there occur additional dynamic loads. In this case, the particular attention is paid to the interaction of the rolling stock and the railway track; to the problems of scientific substantiation of the criteria for assessing the dynamic characteristics of carriages; to the motion smoothness, traffic safety and travelling comfort; as well as to improvement of the maintenance specifications of the track and the rolling stock in the process of their operation and on the basis of scientific analysis and determination of top (safe) speeds of the trains motion.
Using the three-dimensional mathematical model of the DPKr-2 Diesel train waggon, its basic dynamic characteristics were determined and analysed: coefficients of vertical and horizontal dynamics, maximum acceleration of the body both in vertical and in horizontal plane. The influence of the amplitude of vertical and horizontal obliques of the railway track on the dynamic characteristics of the Diesel train was investigated. The determination of the basic dynamic characteristics was carried out on the basis of the developed three-dimensional mathematical model of the waggon, which consists of 38 differential equations of the Diesel train motion. The simulation (solving) of the mathematical model was carried out using Maple software. The geometrical periodic equivalent obliques of the left and right rails were adopted as perturbations both in vertical and in horizontal plane. The determination of the basic dynamic characteristics of the DPKr-2 Diesel trane waggon will allow evaluating its vibro-protective properties. The determination of the coefficients of vertical and horizontal dynamics both in central and in axle leaf-spring suspension, of the maximum accelerations of the waggon body in vertical and in horizontal plane will allow carrying out the analysis of vibro-protective properties of the mechanical part of the Diesel train wagon. The obtained results may be used to define the safe interval of the Diesel train motion speeds on the track sections in the presence of vertical and horizontal obliques.
Keywords: mathematical model; coefficients of vertical dynamics; coefficients of horizontal dynamics; leaf-spring suspension; wheelset.

Кількість посилань 12

Jerzy Jaroszewicz1, Olesya Maksymovych2, Andrii Dzyubyk3, Ihor Nazar4
1 Department of Production Management, Faculty of Management, Bialystok University of Technology,
2, O. Tarasiuka Str., Kleosin, 16-001, Poland, E-mail: j.jaroszewicz@pb.edu.pl
2 Department of Welding Manufacture, Diagnostics and Restoration of Metal Structures, Lviv Polytechnic National University, 12, S. Bandery Str., Lviv, Ukraine, E-mail: olesyamax@meta.ua
3 Department of Welding Manufacture, Diagnostics and Restoration of Metal Structures, Lviv Polytechnic National University, 12, S. Bandery Str., Lviv, Ukraine, E-mail: dar.lviv@gmail.com
4 Department of Welding Manufacture, Diagnostics and Restoration of Metal Structures, Lviv Polytechnic National University, 12, S. Bandery Str., Ukraine, Lviv, E-mail: nazari@ukr.net
DETERMINATION OF STRESSES AND ULTIMATE LOADS
FOR COMPOSITE PLATES WITH ELASTIC INCLUSIONS
Received: October 28, 2017 / Revised: December 20, 2017 / Accepted: December 26, 2017
© Maksymovych O., Dzyubyk A., Nazar I., Jaroszewicz J., 2017
Abstract. In the article, the algorithm for determination of stresses in anisotropic plates with elastic inclusions of another anisotropic material was developed on the basis of complex singular integral equations. The solving of integral equations has been carried out numerically using the method of mechanical quadratures. The strength analysis (calculation of strength) of composite plates with inclusions has been performed using the Hoffman criterion.
Keywords: stress concentration factors; anisotropic plate; elastic inclusion; stress-strain state; singular integral equation; strength analysis; Hoffman criterion.

Кількість посилань 10

Roman Kachmar1, Roman Zhuk2
1 Department of Operation and Repair of Automotive Vehicles, Lviv Polytechnic National University,
12, S. Bandery Str., Lviv, Ukraine, e-mail: roman.y.kachmar@lpnu.ua
2 “Karpaty-logistic” Ltd, 20-а, Nova Str., Malekhiv, Lviv region, Ukraine, ZRV2203@gmail.com
FUNCTIONAL PERFORMANCE OF THE MAIN LIGHTING SYSTEM OF MOTOR VEHICLES
Received: November 20, 2017 / Revised: December 23, 2017 / Accepted: December 26, 2017
© Kachmar R., Zhuk R., 2017
Abstract. Visual perception plays a crucial role in the safety of road users. However, certain conditions such as twilight, the impact of bad weather, dirty windshields, etc. have a negative impact, which in turn increase the likelihood of traffic accidents (TAs) [1]. The ever increasing number of vehicles on the road is an additional potential danger. In response to these factors work is constantly being done to modernize existing and develop new lighting devices.
Vehicular headlights are firstly assigned to optimally illuminate the roadbed in order to ensure safety [2]. For this reason headlights, including their light source, are important safety elements for vehicles, and their application requires official permission. The type and location of vehicular lighting, as well as their design, light source, color and light settings are regulated by law [3].
Automakers pay sufficient attention to the fuel economy and safety of their vehicles. So for this reason automotive light sources, such as incandescent and gas-discharge (HID) bulbs, are increasingly being replaced by LED and laser diode bulbs as they provide superior lighting with lower power consumption. This in turn leads to increased vehicle safety and economy [3].
Keywords: vehicle; lighting system; headlights; lamp; low beam; illumination; power supply; diffuser; blinding oncoming drivers.

Кількість посилань 11

Vitaliy Korendiy
Department of Mechanics and Automation Engineering, Lviv Polytechnic National University,
12, S. Bandery Str., Lviv, Ukraine, E-mail: vitalii.m.korendii@lpnu.ua
STRUCTURAL AND KINEMATIC SYNTHESIS OF THE 1-DOF EIGHT-BAR WALKING MECHANISM WITH REVOLUTE KINEMATIC PAIRS
Received: July 12, 2017 / Revised: September 16, 2017 / Accepted: December 26, 2017
© Korendiy V., 2017
Abstract. Problem statement. The use of existing and the most widespread drives (wheeled and caterpillar one) is sometimes limited by complicated operational conditions while moving on rough terrain. The mentioned drives require a relatively flat surface to be operated effectively. A rocky or a hilly terrain imposes the demand of the use of alternative types of drives, in particular, walking ones. Purpose. In this paper, there will be proposed and analysed one of the possible structures of the walking mechanism for mobile robotic system to be used on rough terrain. Methodology. While carrying out the investigations, the structural and kinematic synthesis of the eight-bar hinge-lever walking mechanism has been performed using the well-known methods of the Theory of Machines and Mechanisms, in particular, the method of closed vector loops. In order to conduct experimental investigations and simulation of the mechanism motion, the applied software SolidWorks and MapleSim has been used. Findings (results). The structure and geometrical parameters of the eight-bar walking mechanism have been synthesized with the aim to ensure the required trajectory and kinematic characteristics of the supporting foot motion. Originality (novelty). The analytical dependencies describing the trajectory of each hinge of the analysed walking mechanism have been derived and the kinematic optimization synthesis problem has been solved. This allowed to substantiate of the mechanism’s geometrical parameters and to analyse its kinematic characteristics. Practical value. The proposed structure of the walking mechanism can be effectively used in various mobile robotic systems and in transporting and technological machines in order to ensure the possibility of their use on rough terrain where there is no ability to use wheeled and caterpillar drives. Scopes of further investigations. While carrying out further research, it is necessary to analyse the influence of the weight coefficients on the solution of the optimization problem, as well as to take into account the necessity of changing the step length and the foot lifting height during the process of walking according to the surface obstacles sizes.
Keywords: walking mechanism; structural analysis; kinematic analysis; synthesis; optimization; objective function; geometrical parameters; trajectory; speed; acceleration.

Кількість посилань 18

Volodymyr Biloborodchenko1, Andrii Dzyubyk2, Andrii Zabranskyi3
1 Department of Welding Manufacture, Diagnostics and Restoration of Metal Structures, Lviv Polytechnic National University, 12, S. Bandery Str., Lviv, Ukraine, E-mail: vbilko22@gmail.com
2 Department of Welding Manufacture, Diagnostics and Restoration of Metal Structures, Lviv Polytechnic National University, 12, S. Bandery Str., Lviv, Ukraine, E-mail: dar.lviv@gmail.com
3 Department of Welding Manufacture, Diagnostics and Restoration of Metal Structures, Lviv Polytechnic National University, 12, S. Bandery Str., Ukraine, Lviv, E-mail: zvdv@ukr.net
INVESTIGATION OF MAGNETICALLY CONTROLLED ELECTRIC ARC
Received: September 15, 2017 / Revised: November 22, 2017 / Accepted: December 26, 2017
© Biloborodchenko V., Dzyubyk A., Zabranskyi A., 2017
Abstract. In this work, the results of pad welding with the circularly rotating arc existing in an inert gas between a circle cathode with the diameter suitable to dimensions and geometry of a welded surface, with the kinematic characteristics of the motion provided (with the rest equal conditions) by the external magnetic field, are considered.
It is shown that the strict theory of an electric arc is insufficient for the description of real physical processes occurred in it under the action of external exciting magnetic fields, and so it does not allow conducting satisfactory technological calculations of the parameters of the pad welding process performed by the arc moved by the external magnetic field. The main problem consists in determining the effectiveness and the direction of superposition of electrodynamic and mechanical forces in it, which resist arc interaction with the magnetic field.
Therefore, the aim of the work is to investigate the influence of the induction value В of the transvers magnetic field of a solenoid inductor on predicted kinematic characteristics of the arc.
The investigations were conducted with the use of experimental equipment (test bench) consisting of a toroidal inductor with a winding. On the inductor, a nonfusible water-cooled ring copper electrode is mounted. Electrode dimensions agree with the diameter of pad surface. The shielding gas is provided through the system of radially located nozzles with discreet valvular operation, whose work priority is agreed with the arc motion velocity by a control unit. Since the values of abovementioned forces directly conditioned by the presence of a magnetic field in an inter-electrode gap, the investigation of its intensity by the electrodynamic method with the help of the measuring instrument for magnetic induction ИМИ-1 was carried out.
The analysis of the superimposed surface of the impact of the magnetizing current and the arc gap, which are used at pad welding by magnetically controlled arc, on the field induction shows that the range of their influence as technological mode parameters is quite narrow. Accordingly, for optimal choice of model nomographic solutions and the description of the correlation of parameters of the arc gap and magnetizing current, which provide the technologically suitable induction, an experiment was conducted according to the matrix of simplex-summarized С-С2 design. The investigations of a model extremum shows the acceptable induction value of 850∙10-5Т for the length of the electrode gap of 4 mm and inductor magnetizing current of 6 A.
As a result, the proposed design of the test bench satisfies the geometrical parameters of renovated workpiece and enables using the effective repeated thermal pad cycle per unit of the surface by the rotating arc in the stable magnetic field. Settings of the magnetically operated arc, which provide the necessary value of field induction in the inter-electrode gap, can be determined either by nomograph solution, or by the strict statistic models. The influence of the length of the inter-electrode gap on the choice of the induction value is limited by technologically suitable pad current and corresponding length of an arc column. The main setting and controlling parameter of the magnetic field mode is the inductor magnetizing current. The force of resistance to arc motion at the stage of arc development and at the stage of arc steady motion is directly proportional to the value of the pad current. Calculated values of the velocity of arc motion at given values of the pad current are in the range relevant to its steady motion and provide the processes of anode melting without thermal damaging the ring cathode.
Keywords: pad welding; circularly rotating arc; inert gas; magnetic field; induction; inter-electrode gap; pad current; anode melting; magnetizing current.

Кількість посилань 15