• MACHINES

    DESIGN PROCESS FOR THE SUSPENSION SYSTEM OF THE TERRAIN VEHICLE WITH FOUR WHEEL DRIVE

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 10, pg(s) 477-480

    This paper discusses the research methodologies utilized for developing a suspension system for a four wheel-drive terrain vehicles. The main research methods can be identified as literature studies; design processes by applying CAD systems, numerical analyses methods, mathematical modeling and simulation, optimization of the mechanical systems, as well as the comparison, analysis, and evaluation of the obtained results. The proposed suspension system for the terrain vehicle was successfully derived at from a classic double wishbone control arm. Optimization of the suspension parameters for passive ones is performed by Multi Objective Genetic Algorithms, whilst for active damping force by employing Hooke-Jeeves non-linear programming method. On the basis of comprehensive analysis it is shown the active systems are more adequate. The proposed suspension design provides relatively small lateral wheel motion, zero camber angles, and effectively absorbs the vibrations caused by road excitation.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    RESEARCH AND ANALYSIS OF DYNAMIC PARAMETERS IN V-BELTS

    Trans Motauto World, Vol. 2 (2017), Issue 6, pg(s) 235-237

    In this work is presented research about main dynamic parameters that have influence in the efficiency of trapezoid belts (VBelts). Research is done in the testing machine with 3 wheels. Two main parameters analyzed are important dynamic parameters: Force of preliminary belt tightening (Fpr), and Coefficient of elastic slipping (Kes). Last coefficient is important factor for dynamic analysis of belt transporters while it defines clearly level of carrying capacity vs. defined force of preliminary belt tightening. Through laboratory testing has been researched influence of power that is transmitted and force of preliminary tightening in the coefficient of elastic slipping, with the aim to determine optimal limit of this coefficient. In practice it is recommended that values of this coefficient not to be higher than 2%.

  • MACHINES

    MATERIAL DEFORMATION ANALYSIS IN BRIDGE CRANE DURING TRAVEL MOTION WITH FULL LOADING

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 8, pg(s) 389-392

    This paper deals with dynamic analysis of bridge crane with single girder in order to determine material deformations in their main parts – cables and girder’s, while moving and carrying load. It is known that these are mostly loaded parts in crane, while they accept forces, moments and oscillations from lifting mechanism and load. Analysis will be accomplished using computer modeling and simulations. Work process of crane in the study is forward travel motion. It is assumed that this motion process makes major impact in the deformations of lifting cables and girders due to stress, oscillations, and negative effect of load swinging. The analysis will be concentrated in finding the nature of oscillations that acts on crane and finding the extent and form of materials stress and deformations that can cause fatigue, failures and accidents. Question is whether acting loads exceed elasticity limits, or there are plasticity deformations which lead to permanent damages. Results will be shown in the form of diagrams, contour stress and strain in cables and girders. They will be compared with experimental measurements. Conclusions of these analyses can be useful for design considerations and safety.

  • TECHNOLOGIES

    TOOL LIFE MODELING BASED ON CUTTING PARAMETERS AND WORK MATERIAL HARDNESS IN TURNING PROCESS

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 7, pg(s) 356-359

    In this paper we have presented methodology for development of life prediction model for first order tool during turning of hardened 42CrMo4 steel at different levels of hardness. It is important to be able to predict and describe the tool life in regards to manufacturing costs during industrial production. Tool life is defined as the of cutting time that tool can be used. Cutting tools can be used when they do not reach tool life criteria and can produce parts with desired surface finish and dimensional accuracy. Flank wear of cutting tools is often selected as the tool life criterion because it determines the diametric accuracy of machining, its stability and reliability. Tool wear is defined as a gradual loss of tool material at contact zones of workpiece and tool material, resulting the cutting tool to reach its life limit. This paper investigates the tool wear of TiN coated tungsten carbide inserts under dry cutting, using the central composite design of experiments method (DoE) with three factors at three levels. By using the multiple linear regression analysis between cutting speed, feed rate and depth of cut, it determines the effects of cutting conditions on extended Taylor’s tool life equation.

  • MATHEMATICAL MODELLING OF TECHNOLOGICAL PROCESSES AND SYSTEMS

    COMPUTER AIDED ANALYSIS OF KINEMATICS AND KINETOSTATICS OF SIX-BAR LINKAGE MECHANISM THROUGH THE CONTOUR METHOD

    Mathematical Modeling, Vol. 1 (2017), Issue 1, pg(s) 51-56

    In this paper is presented a six-bar linkage mechanism of the pump for oil extrusion. In this mechanism are introduced higher kinematic pairs. Dimensions and other incoming links are adopted as necessary. For the six-bar linkage mechanisms is carried out the kinematic analysis and for all linkages are shown the displacement, velocity and acceleration. The analysis is performed by Math Cad software, while kinetostatic analysis is carried out using Contour Method, comparing results of two different software‘s Math CAD and Working Model. The simulation parameters are computed for all points of the contours of mechanism.