Mobility and Vehicle Mechanics

Number 3, 45

1-11
MULTI-CRITERIA OPTIMIZATION OF SINGLE INTERSECTION UNDER OVER-SATURATED CONDITIONS

Authors: Aleksandar Jovanović, Dušan Teodorović

Abstract

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Number of views: 245

Intersections are junctions where at least two roads or streets meet or cross. Consequently, they represent the most critical spots in the city traffic network, in terms of traffic safety. When determining the Level of Service at signalized intersections, the Highway Capacity Manual (HCM) does not take into account the traffic safety factors. In order to overcome this shortcoming, we propose in this paper the multi-criteria approach to the single intersection traffic control problem. The first objective function to be minimized is the average control delay experienced by all vehicles that arrive at the intersection. The second objective function to be minimized is the traffic safety risk index on intersection. These two criteria are in conflict, and the task is to find a good compromise between them. The analysed problem is solved by the combination of dynamic programming, and compromise programming. The proposed approach was tested in the case of the intersection that is controlled with two phases, under over-saturated traffic flows.

13-23
LIFE CYCLE ASSESSMENT OF THE CAR TIRE WITH ECO INDICATOR 99 METHODOLOGY

Authors: Angelina Pavlović, Danijela Nikolić, Saša Jovanović, Goran Bošković, Jasmina Skerlić

Abstract

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Number of views: 385

Today automotive industry is a driving force for development of national economics so number of vehicle increases expeditiously. As an integral part of the vehicle, tires are generated annually in large amount all over the world. Growth of the car tires production affect environment and also the growth of non-degradable waste which has a large energetic potential but which currently is not fully used. The aim of this study is to evaluate the environmental impact of car tire during its whole life cycle and to identify activities in life-cycle phases that can be improved. That analysis can be achieved throughout its service life, from the acquisition of the raw materials through to the recycling of the worn tire, because the tire constantly interacts with the environment. Approaches to effectively reducing the negative environmental impact can be demonstrated only on the basis of detailed knowledge of this interaction. This is why a life cycle assessment quantifies the material and energy flows in the different stages of a tire’s life cycle (life cycle inventory analysis) and describes the interaction with the environment (impact assessment and interpretation). In this study, environmental impact is evaluated by using methodology Eco Indicator 99, which is one of the most widely used impact assessment methods in Life Cycle Analysis (LCA).

25-39
FAILURE MODE, EFFECTS AND CRITICALITY ANALYSIS OF MECHANICAL SYSTEMS’ ELEMENTS

Authors: Dobrivoje Ćatić, Jasna Glišović

Abstract

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Number of views: 508

Basic concepts and a brief history of the development of Failure Modes, Effects and Criticality Analysis - FMECA are given in the introductory part of the paper. In the present considerations, the quantitative FMECA is based on the assumption that the intensity of the element’s failure is constant and is mainly applied in electronic systems. Based on the current procedure, taking into account the specificity of the mechanical system’s elements in terms of the intensity of the failure, the proposal of the quantitative FMECA of these elements is given. The procedure has been expanded with a step of determining the absolute criticality of the elements from the aspect of reliability and functional safety. The application of the procedure is illustrated through the case of determining the criticality of the elements of the light commercial vehicle’s steering system based on exploitation data.

41-50
CONTROL STRATEGY FOR AFTERMARKET ELECTRONIC THROTTLE CONTROL

Authors: Jelena Prodanović, Boris Stojić

Abstract

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Number of views: 373

This paper presents the development of electronic throttle control, provided for use in an experimental light hybrid-electric vehicle that was a final product of ongoing student project. Originally, the IC-engine throttle system was operated using mechanical linkages and cable, which was enhanced by developing a new system containing sensors and actuators. Therefore prototype of such a system had to enable the possibility of exerting control of both IC engine, powering the rear axle, and two electric hub motors, powering the front axle, by using the single accelerator pedal. This way full exploitation of hybrid drive potentials can be enabled.

51-64
APPLICATION OF NANOCOMPOSITES IN THE AUTOMOTIVE INDUSTRY

Authors: Sandra Veličković, Blaža Stojanović, Lozica Ivanović, Slavica Miladinović, Saša Milojević

Abstract

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Number of views: 811

The development of new lightweight and strong materials and the design of new products are among the key elements for the development of new advanced construction and vehicle parts for the automotive industry. The use of composite materials in the automotive industry has been popular in recent decades due to the need to reduce vehicle weight, which directly affects fuel consumption and exhaust gases emission. In this way, the development of improved new materials with improved performance is accomplished. Nanocomposites represent a new class of materials that has excellent thermal and mechanical properties. The application of nanocomposites for development of automotive components is reflected in the improvement of the production rate, environmental and thermal stability, and the reduction in weight in the automotive industry, less wear parts, and indirectly to reduce CO2 emissions and environmental pollution. This research paper presents a review of the application of nanocomposites (metal, ceramic and polymeric) in the automotive industry.