Table of Contents

  • SIMULTANEOUS RESONANCE CASES IN A PITCH – ROLL SHIP MODEL. PART 2: NUMERICAL ANALYSIS

    pg(s) 1-1

    In a companion paper, the response of a two-degrees-of-freedom ship model with nonlinear coupled pitch and roll modes under sinusoidal harmonic excitation was studied analytically by means of the Multiple Scales method for the case where the pitch frequency is twice the roll frequency. Five resonant cases were analysed and the governing equations for the transition towards the steady-state solutions, the first-order approximations for these solutions and the frequency-amplitude relationships were derived. The present contribution aimed to verify the accuracy of the analytical results by contrasting them with the numerical results provided by direct integration of the equations of motion. The two sets of results were found to be in excellent or, at least, in decent agreement every time the system parameters were selected without a flagrant violation of the order’s magnitude.

  • SIMULTANEOUS RESONANCE CASES IN A PITCH – ROLL SHIP MODEL. PART 1: FIRST – ORDER APPROXIMATE SOLUTIONS

    pg(s) 10-13

    In the paper, a two-degrees-of-freedom ship model with quadratic coupled pitch and roll modes under sinusoidal harmonic excitation is considered. The Multiple Scales perturbation technique is applied to yield the first-order expansions for the special internal resonant case where the pitch frequency is twice the roll frequency. Increasing the wave frequency from zero to infinity, five resonant situations are detected. For each case, the governing equations for the transition towards the steady-state solutions, the first-order approximations for these solutions and the frequency-amplitude relationships are presented. A detailed analysis is performed only for the case where the excitation frequency is half of the roll frequency. The reliability of the analytical results derived in the paper is checked in a companion contribution by comparison with numerical solutions.

  • CREATION OF ACCUMULATION AND STORAGE OF ELECTRICAL ENERGY FOR DRIVERLESS ELECTRIC VEHICLES OF RUSSIAN PRODUCTION

    pg(s) 18-21

    In recent years, many researches in the field of electromobile transport using as driverless vehicle are carried out in Russia as in the world. Operation electromobile transport in Russia has specific features, among which are the cold climate and heavy traffic conditions. One of the key elements of the functioning of electromobile transport is an energy storage system, the characteristics of which are highly dependent on how and under what conditions the vehicle is operated. The life of the energy storage system is also adversely affected by high temperature and short overvoltage on its elements. To increase the mileage of vehicles on the electric energy storage provides an improved system design, and in this article the experience of creating such an energy storage system for the driverless vehicle, taking into account including the Russian operating conditions. In the process of creating energy storage system were carried out calculations, mathematical and natural layout the basic elements of the system.

  • QUALITY MANAGEMENT AND PRACTISES IN AUTOMOTIVE PARTS PRODUCTION

    pg(s) 22-25

    This paper comprises an analysis of an automotive industry company in order to identify whether it has an effective quality assurance system, by monitoring the manner business processes are managed (identification, documentation and control) and whether system efficiency documentation has been developed. The application of different standards/systems for: quality, environment, employee health and safety, corporative social responsibility, food products safety, etc., requires new manager proactive management style and system orientation, as well as reengineering of business processes. However, for successful operation, it is not enough to develop a system that will provide designed quality, but also the costs to implement business processes are significant. In this paper, by applying the Pareto method for detection of points where most defects occur, the Ishikawa approach which reveals the causes of errors, checklists, as well as the Quick Response Quick Control methodologies; 8D (Eight disciplines); PFMEA, the business processes for procurement of raw and repro materials was optimized. The obtained results show that the implementation of these methodologies to optimize business processes leads to the defined quality and better productivity at the lowest costs in operation.

  • AN ANALYTICAL MODEL OF THE MOTOR-GRADER MOVEMENT AT PERFOMING WORKING OPERATIONS

    pg(s) 26-32

    A major part of working operations performed by a motor-grader is accompanied by asymmetric action of the resultant vector of external resistance forces applied to the main blade. The eccentrically applied horizontal loads together with additional lateral forces affect the parameters of the machine road-holding ability resulting in deviation of its actual trajectory from the planned one. In the presented work on the basis of the developed model there have been analyzed the impact of operational characteristics of the working process on the indicators of the machine road-holding ability.

  • THE PARAMETRIC OSCILLATIONS OF STEEL FRICTION PLATES FOR A MULTIPLATE CLUTCHES

    pg(s) 3-6

    The article substantiates the ways of tuning parametric oscillations providing for increasing durability of steel and friction plates of vehicle transmissions. The evaluation of dynamic stability is conducted on the basis of the analysis of Mathieu equation and Ince-Strutt diagram. It is offered to restrict the parameter of rigidity modulation depth by filtering low-frequency disturbances formed in the nonlinear system by the power unit (internal combustion engine (ICE) or electric motor (EM)), by hydrodynamic processes in the hydraulic transformer (torque converter or hydraulic coupling) and in the system of its oil supply. The performance evaluation of the developed actions on plate’s durability is conducted.

  • PROPOSAL MODERNIZATION OF NITRA – LEOPOLDOV TRACK SECTION

    pg(s) 33-35

    The development of the regional rail transport requires impulses mainly from the infrastructure manager, in particular structural modifications of tracks. The technical and constructional layout of stations and track sections and its accessories could be change by build-constructional measures. The negative site of it is high costingness and time consuming for realization past normal traffic operation. This paper extends a general overlook on a draft of a modernization of regional lines to ensure required quality in railway transportation. The proposals are applicated for Nitra – Leopoldov track section.

  • IMPROVEMENT OF THE BARGE HULL BY OPTIMIZATION OF ITS RIGIDITY PARAMETERS

    pg(s) 36-39

    The article discusses optimization of barge hull by decreasing of its mass parameters by changing of thickness of the plates. The fish-feeding barges are usually used in calm water and in this case it is possible to consider only static loads applied on the barge hull.

    There are many calculation methods for determining stress and deflections in the thin plates. A lot of them are using uniformly distributed load and constant thickness of the plate. In real conditions, a hydrostatic pressure is applied on the barge hull. In this research, we consider a calculation method of thin plates taking into account variable thickness of the plates and non-uniformly load. In addition, we try to show by experiments and FEM analysis the possibility to use variable thickness of barge hull in building of fish-feeding barges.

  • FACTOR ANALYSIS TO CALCULATE THE RIVER CAPACITY

    pg(s) 40-43

    A waterway is not consists of sections have constant loading gauges and – because of this – constant throughput capacity. The waterway categories themselves are suggesting to the different capacities, however the effective quantification is a significantly more complex task. The navigable section of a river consists of heterogeneous lines with space and time-varying characteristics because of its morphology and hydrology. The study examines the factors to prepare specific calculation.

  • FIGHT AGAINST POLLUTION IN CAR INDUSTRY – WORLD TRENDS

    pg(s) 44-46

    The expansion of our needs in the space and many changes around us requires a change in attitude towards the environment. Research suggests that by 2030 in the world there will be 8.5 billion people. Planet is warming up and there is an increasing frequency of natural disasters: heat waves, floods, hurricanes. The public is aware that air pollution kills 3,3 million people per year. It is necessary to react quickly. In Paris at the end of 2015 the 21-st Conference of the UN on climate changes (COP 21) was held.

    Serbian association of importers reported that in recent years in our country about 20.000 new cars and about 100.000 used cars was imported. In Serbia there is no laboratory that could to accurately test the amount of exhaust gas according to European standards in effect. In our country still is in force the Regulation on technical inspection from 1984, so the allowed values of exhaust gases are completely downgraded. Today, in our capital city Belgrade we have been working on the improvement the identity of capital, as well as mobility and ecology. In 1892. in Belgrade the first Belgrade’s tram – by a horse-drawn started, but during 2016, passengers will be transported by 5 electric buses of the Chinese company “Hager” with 10 years guarantee.

    Hoping to realize the idea of manufacturers from all around the world, especially that pollution is reduced, and the environment in which we live protected, this work originates.

  • POSSIBILITIES OF USING TRAIN UNITS WITH TILTING SYSTEM IN REGIONAL LINES

    pg(s) 47-49

    The paper is focused on a benefit of urban traction units with tilting system particularly in regional transport, on reducing travel times and on increasing the competitiveness of railway transport. The paper describes the importance of its utilization in such traffic especially if the infrastructure is unable to provide options of higher efficiency for railway undertakings. In this cases are the investments for line optimization not available, so railway undertakings cannot be more efficient by usage of classical vehicles. There is space for research of the possibilities of increasing the quality of transportation process despite the state of the infrastructure.

  • PROSPECTS FOR DEVELOPMENT OF REGIONAL TRANSPORT-TOURIST ROUTES ON THE BASE OF KOPITNARI AIRPORT

    pg(s) 50-52

    The King david the Builder Kutaisi (Kopitnari) International Airport is located in the Black Sea region of the South Caucasus. The Airport’s strategic geographic position and further improvement of the infrastructure allow for its transforming into the regional hub for providing transport services to travelers.

    In the 1980s, the flights from this airport were carried out as inside the country (Tbilisi, Sokhumi, Batumi, Mestia), so outside country as well (Moscow, St. Petersburg, Kiev). The Kopitnari Airport was opened after reconstruction in 2012. Its priorities are attraction to attract low-tariff airline companies and create a harmonic environment between the airline companies and airports. As of today, the flights from the Airport are carried out to Eastern Europe, Turkey and Russia.

    The Airport has the capacity to carry out domestic flights for small tourist groups to: highland ski runs in Mestia; well-appointed Black Sea beaches in Batumi; wine tours in Telavi and so on. Proximity to the trunk railroad and motoring highway are the opportune occasions to form the Kopitnari Airport as a synergic transport system.

    Besdies, the Airport’s proximity to the Rioni River can be used for organizing there the short tour of the so-called “Travel of Argonauts to Kolkheti”, which was passed by the well-known traveler Tim Severin by his oared boat named “Argo” in 1984, and the place where he finally dropped anchor was near the Kopitnari Airport.

  • A METHOD OF VEHICLE-PEDESTRIAN ACCIDENT RECONSTRUCTION

    pg(s) 7-9

    In this work a method of vehicle-pedestrian accident reconstruction in case of unlimited driver visibility and accelerating vehicle moving is presented. This method presents are mathematical models for determining the pedestrian visibility time, vehicle speed at the moment of impact, time to vehicle move from the moment of the hazard occurrence until the moment of impact, the vehicle distance from the place of impact, stopping distance, etc.