Machines. Technologies. Materials.
Vol. 11 (2017), Issue 6

Table of Contents

  • MACHINES

    • SIMULATION OF VERTICAL QUARTER CAR MODEL WITH ONE AND TWO DOFs

      pg(s) 261-263

      This paper deals with the simulation of vertical displacement vehicle car body with one and two DOFs by using and comparing results of two softwares Working Model and MatLab. The aim of this paper was to show that is very easy is to solve the differential equations that describe both models of vehicle system with one and two DOFs. The results simulations performed with both software’s are almost the same for calculating displacement and velocity of sprung and unsprung mass and for different road excitations. The results of simulations have been analysed in terms of stability and road holding since sprung mass or vehicle body oscillations have direct impact on the passenger comfort.

    • INFLUENCE OF COMPONENT POSITION ON THE TABLE DURING ANGULAR ROBOT MACHINING ON ACCURACY IN AUTOMATED SYSTEMS

      pg(s) 264-267

      Use of an industrial robot in the automatic production process as a spindle carrier is currently an interesting topic. However, if the stiffness of the robot is not sufficient, various imprecisions may occur during machining. The article deals with monitoring and evaluation of the impact of cutting conditions and positions of the workpiece in the working area on machined surfaces oriented in orthogonal planes. The aim of the experiment is to analyse the precision of simple planar surfaces milled using a robot

    • DEVELOPMENT OF SCHEMATIC DESIGN MODEL OF GANTRY CRANE FOR DYNAMIC ANALYSIS AND REGULATION OF TRAVEL MOTION

      pg(s) 268-271

      This paper deals with Dynamic analysis of Gantry Crane using Method of Schematic Design which implements schemes with block diagrams to analyze machines and their parts during work process. This procedure is new to analysis of Gantry crane dynamics and consists of crane model development of interconnected elements that represents crane parts, 3-D visualization and motion of crane. Dynamic analysis will be carried through simulations and solution of Euler differential equations of second order gained from schematic design. Simulations will be planned and applied for regulation of travel motion with hanging load. Diagrams with results of main dynamic and kinematic parameters will be presented for main parts of crane as the solution results of the analyzed system. Results gained will be used to get conclusions about dynamic behavior, optimal motion regulation and safety during work. Analysis will be done using modeling and simulations with computer application MapleSim.

    • EXAMINING THE PARAMETERS OF A SYSTEM FOR SUPPLYING SPARE PARTS WITH CONTINUOUS STOCK FILLING

      pg(s) 272-275

      The structure of the system for supplying spare parts for tractors and self-propelled agricultural equipment has been examined. A centralized system of continuous inventory replenishment has been investigated and the influence of the basic parameters of the supply system on the probabilities of refusal of execution of requests is determined.

      It has been shown that the most significant impact on performance indicators of the spare parts supply system is the demand flow intensity.

  • TECHNOLOGIES

    • PRINCIPLES OF DESIGNING AND DEVELOPING INTELLIGENT MANUFACTURING SYSTEMS OF PACKAGING

      pg(s) 276-279

      Manufacturing facilities employing the elements of intellectual technologies can be encountered in various industries. The given paper provides examples of intelligent devices of manufacturing packaging systems. It shows how to maintain operational performance in case of unforeseen changes in the properties of an intelligent manufacturing system by changing the operation algorithm, changing the program behavior or searching for optimal or effective solutions and states during operation.

    • DETERMINATION OF TURNING CENTER MANUFACTURING POSSIBILITIES IN THE FLEXIBLE MANUFACTURING SYSTEM

      pg(s) 280-283

      Flexible Manufacturing Systems provide a fast reaction possibility to the changes in production conditions. As production conditions change, other changes in the final product like changes of the product variants, or other unpredictable events may be also expected. Nowadays most of the products are designed by using the CAx software. The product design 3D model contains not only the geometrical data of product, but may contain a part of the process plan and technological data as well.

      This fact is a reason to quick reaction time possibilities in the manufacturing system settings.

    • CLASSICAL PROBLEMS OF THE TURBULENT BOUNDARY LAYER

      pg(s) 284-286

      Traditional concept about the boundary layer structure, technique of the theoretical determination of a velocity profile in this layer, developed in first half of the 20th century, does not experienced, basically, any changes, although, on their close analysis a number of questions and even problems arises requiring their solution.

      First of all, it is referred to physical causes of the occurrence of turbulence in the boundary layer, conservation of its near-wall region, conformance of a classical logarithmic velocity profile to experimental data, the appropriateness of introduction of such definition as “a laminar sublayer in the turbulent boundary layer”. All these outstanding problems are considered in the following materials.

    • GRAPHENE SUPPORTED CATALYST FOR ENHANCED BIOMASS HYDROLYSIS

      pg(s) 287-290

      The present work reports on a new silicotungstic acid catalyst supported on graphene (HSiW/G). The deposition was performed by sonochemical method proven as an effective technique for the synthesis of the supported catalysts. The catalyst (HSiW/G) was characterized using a variety of physico-chemical methods as TEM, HR SEM, DLS, FTIR and Raman spectroscopy. Homogeneous distribution of HSiW on the surface of graphene was demonstrated. Hydrolysis of biomass for the production of glucose was studied. The hydrolysis of glycogen was performed with a HSiW/G catalyst by hydrothermal treatment. The yield of glucose (65 wt%) obtained was about 8 times higher than that obtained with the same amount of bare HSiW. Stability of the HSiW/graphene even after 3 repeated uses was confirmed. The mechanism of enhancement of the catalytic activity was discussed in terms of a special interaction between the graphene support and HSiW and also the appearance of hydrophobic cavities on the surface of graphene.

    • NON-CHEMICAL WATER TREATMENT IN UNIFIED LIGHT AND SOUND FIELD AND TESTING ON WASTE WATER DECONTAMINATION

      pg(s) 291-295

      The paper presents the results of testing of a high-performance method for decontaminating sewage, involving combination of ultrasonic and ultraviolet exposure at the final step of water purification aimed at destroying pathogenic microorganisms and thereby preventing the spread of infectious diseases.

      A variation of the method was developed and patented by the authors and passed the test at one of the most advanced water facilities in Russia which is the Vodokanal of St. Petersburg. The combined unit was manufactured at OOO Novotech-EKO and installed at the South-West Wastewater Treatment Plant (SWTP) of Vodokanal of St. Petersburg.

      The results of the test showed the efficiency of combined ultraviolet and ultrasonic wastewater treatment, both in terms of intensifying disinfection and in terms of the stability of the plant operation by preventing biofouling and salt deposition on the surface of the lamp casings. The latter fact was the basis for the pilot project of improvement of the existing system of UV waste water disinfection at the SWTP

    • DEVELOPMENT AND APPLICATION OF THE ULTRASONIC TECHNOLOGIES IN NUCLEAR ENGINEERING

      pg(s) 296-300

      Efficiency of some traditional chemical technologies in different areas could be significantly increased by adding ultrasonic treatment. For example, ultrasonic treatment was found to improve make-up water systems, decontamination procedures, etc. Improvement of traditional chemical technologies with implementation of ultrasonic treatment has allowed to significantly reducing water waste, including harmful species and radioactive products.

    • FEM 2D AND 3D DESIGN OF TRANSFORMER FOR CORE LOSSES COMPUTATION

      pg(s) 301-304

      Accurate simulation and prediction of losses in power transformer is important during transformer lifetime but also during the design stage. Paper presents the simulation model of transformer based of Finite Element Method that allows calculation of core losses and magnetic flux density in transformer cross-section. Two different models are constructed for 2D and 3D simulation. Obtained results are compared with experiments. Finally, flux density in both models is calculated and obtained results are presented for different time steps.

    • EFFECT OF ADHESIVE TYPE ON THE QUALITY PROPERTIES OF PARTICLEBOARD

      pg(s) 305-306

      The objective of the present study was to investigate the effect of adhesive type on physical and mechanical properties of particleboard. Three types of adhesives, urea-formaldehyde, melamine-urea formaldehyde adhesive, and acrylic adhesive, were used in the production of lab scale particleboards with three layers. The particleboards produced with the acrylic adhesive had the best physical and mechanical properties, followed by MUF adhesive, and UF adhesive, respectively. The lowest formaldehyde emission was observed for the acrylic bonded particleboards, followed by MUF, and UF adhesive bonded particleboards, respectively. Based on the findings obtained from the present study, the acrylic adhesive can be efficiently used in the production of particleboard.

    • IMPROVING THE RELIABILITY OF AGRICULTURAL MACHINERY, USING THE METHOD OF RESTORATION OF PARTS UNDER SUBMERGED ARC WELDING, AND ITS TECHNICAL AND ECONOMIC EVALUATION

      pg(s) 307-310

      The basic features of calculating the reliability of agricultural machinery are shown, in contrast to industries such as mechanical engineering, radio and television equipment, automation systems and etc., in which machines and apparatus operate in steady modes, while agricultural machines do in difficult soil and climatic and dynamic conditions.

      Еconomic aspect of reliability is substantiated and patterns of change in the efficiency of use of agricultural machinery in time are established, the economic parameters of reliability are determined. With the help of the theory of similarity and dimensions as well as the planning of multifactor experiments, through the original installation manufactured by us, the basic physical and mechanical properties of metal coatings are studied, obtained by welding under flux, there are relevant similarity criteria determined that characterize the process of restoration of worn parts and, after processing of experimental data an analytical view of criterion equation is formed and rational modes of the restoration of parts under submerged arc welding are set. Further, to optimize the process, the scheduling theory of extreme experiments has been used and as factors in the regression equation there have been chosen most significant similarity criteria. In methodics elaborated by us, it was obtained an adequate equation and by a method of steep ascent (movement along the gradient), there were determined optimal modes of recovery for metal coatings with high physical and mechanical properties (hardness, wear resistance).

      Under these regimes there were recovered worn ploughshares and their operational check showed an increase of resource as many as 1.4…1.5 times. For surfacing worn parts with complex configurations (ploughshare plows, cultivators paws), we have manufactured a special copier allowing to recover the items automatically, in a continuous mode. The feasibility study of the developed resource-saving innovative technology has shown that the restoration of 800 ploughshares provides an yearly economic effect of EURO 1,462.

    • APPLYING A MODIFIED VARIATIONAL ITERATION METHOD TO THE PLUNGE GALLOPING EQUATION

      pg(s) 311-314

      The plunge galloping is a high-amplitude, low-frequency oscillation of a slender structure, such as iced conductors of a power transmission line or bridge decks, essentially perpendicular to the wind direction. In the paper, an idealized model for the plunge galloping is shortly reviewed and then a slight modification of the variational iteration method, applicable to weakly nonlinear problems, is employed to obtain a system of two amplitude-frequency equations that provide both the transitional and long-term behaviours. The approximate analytical results derived in the paper have been applied to a typical section model and the numerical results are contrasted with those provided by the direct integration of equation of motion.

  • MATERIALS

    • TRANSFORMATION OF HETEROPHASE NON-METALLIC INCLUSIONS “HIGHMELTING PHASE SURROUNDING WITH LOW-MELTING COVER” IN STEELS UNDER LASER ACTION

      pg(s) 315-319

      Melting and crystallization of heterophase non-metallic inclusions “high-melting phase surrounding with low-melting cover” was investigated. It was shown that under laser action the initial structure of inclusion-steel matrix boundaries transits into unstable equilibrium high-energy condition that cause development of the dissipation processes connecting with aspiration of system inclusionmatrix to the state with minimum of free energy. In the result of the system heterophase inclusion-matrix transits to the state of unstable equilibrium which determines structure and properties of laser-quenched interphase boundary. Processes of melting, fusion and dissolution of non-metallic inclusions “high-melting phase surrounding with low-melting cover” and also of the melting of steel matrix play the great role in transformation of interphase inclusion-matrix boundaries under laser action.

    • MODEL ADHESION WEAR OF FRICTION SURFACE

      pg(s) 320-322

      The article deals with forming the adhesive bond of bodies at the crystal lattice level. There is offered a mathematical model for determining the adhesion wear. There are carried out laboratory tests for model validation. There is found that the amount of adhesive wear is nonline-arly dependent on the surface roughness inclination angle.

    • THE IMPACT OF TRIBOCORROSION ON WEAR OF WORK PARTS OF THE SCREW PRESS

      pg(s) 323-326

      In the production of oil in the oil mill parts of the equipment wear due to contact with seeds which contain microabrasive particles. This wear manifests itself by changing the dimensions and geometry of the screw press. The paper analyzes the influence of tribocorrosive wear on the workpieces of the screw press. The appearance of wear is most likely due to the action of aggressive media, in this case the oilseeds. In the experimental part of this paper, on samples made of cast steel and austenistic stainless steel, following laboratory tests were performed: electrochemical testing, testing of chemical composition of the base material, wear analysis, microstructure recording and hardness testing. Based on the laboratory testing, conclusion was that the austenistic stainless steels 304L and 316L with nitrated surfaces exhibit better resistance to tribo-corrosion wear in relation to cast steel GS-42CrMo4.