• TECHNOLOGIES

    THE METHODOLOGY FOR VEHICLES PARKING ANALYSIS: CASE STUDY – CITY OF PRISHTINA

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 10, pg(s) 499-503

    Cities are faced with many challenges, in particular in relation to the mobility of people and the structure of land-use. Parking management, which makes the link between the fields of urban planning and transportation, is one of the crucial ways to meet these challenges.

    The problem of parking in the capital of Kosovo in Prishtina is a major concern for the citizens and central and local authorities. For the purpose of easier parking problem study, the first ring of the center zone of Prishtina is divided into XI sub zones. During the collection of data directly from XI sub zones through the observation- survey method, it was noted that the biggest problems are in the sub zones II. Therefore, in this paper is analyzed sub zone II through the parking statistics such as parking causes, accumulation, parking loads, parking duration. After the analysis, findings are made on the choice of the parking problem for this sub zones.

  • MATHEMATICAL MODELLING OF TECHNOLOGICAL PROCESSES AND SYSTEMS

    ROTATIONAL MOTION OF TOWER CRANE – DYNAMIC ANALYSIS AND REGULATION USING SCHEMATIC MODELING

    Mathematical Modeling, Vol. 2 (2018), Issue 1, pg(s) 21-25

    This paper deals with dynamic analysis of particular type Construction Cranes known as tower crane during rotational motion of its jib. Methodology of analysis consists of Schematic Design of model, which implements schemes with block diagrams to analyze cranes and their parts during particular work cycle. This procedure consists of crane model development of interconnected elements that represents crane parts, 3-D visualization and simulation of motion. Analysis will be carried out through simulations, and solution of Euler differential equations of second order gained from schematic model. Dynamic parameters investigated are: acceleration, angular velocity, forces and torques in main parts of crane, and influence of load swinging. Diagrams 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 of crane, present graphs of main parameters and search for regulation of optimal jib rotation. Analysis will be done using modeling and simulations with computer application MapleSim. Also, results gained from simulations will be compared with those from experimental measurements.

  • 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.

  • MACHINES

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

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

  • MACHINES

    THE INFLUENCE OF LUBRICATION OILS AND FILTERS ON THE OILS PRESSURE, TEMPERATURES AND FLOW DURING ENGINE WARM-UP AT SUMMER CONDITION

    Machines. Technologies. Materials., Vol. 10 (2016), Issue 10, pg(s) 13-16

    The key issue to an automotive engine’s reliability and its durability is the quality of the lubrication system. The primary task of the lubrication system is to provide a continuous supply of filtered oil between two sliding surfaces. By using adequate lubrication oils will reducing friction between moving mechanical parts. Rheological characteristics of lubricating oil directly caused the friction losses due to internal engines mechanisms (piston group, valve train, fuel pump, crankshaft, bearings and seals, etc.). The main components of lubrication system has a poor lubrication during cold start up process of an IC diesel engine and thus is necessary a proper lubricating oil to full fit the complex demands of all engine components and subassemblies. The aim of this paper is experimental investigating of the influence for different classes lubricating oils characteristics and oil filters which are present in market of Republic of Kosovo, especially those with lower prices on engine oil pressure, temperature and flow during start up until the oil warms up some. The obtained results are taken from measuring device which is installed into Fiat passenger car with Spark Ignition Engine for different working regimes.

  • MACHINES

    TRUCK MOUNTED CRANES DURING LOAD LIFTING – DYNAMIC ANALYSIS AND REGULATION USING MODELLING AND SIMULATIONS

    Machines. Technologies. Materials., Vol. 10 (2016), Issue 8, pg(s) 12-15

    Truck Mounted Cranes are used for load lifting and lowering, mainly in construction industry for materials handling. These cranes have complex structure with many parts and mechanisms with bars, linkages, actuators, cables, outriggers, etc. Using modeling and simulations with software we will analyze dynamics and oscillations in crane while lifting the maximal load, and methods of control of these oscillations in order to optimize the work process of truck crane. Dynamic parameters analyzed are: velocity, acceleration, angular velocity, forces and torques that act in main parts of crane, including load swinging. The study will be accomplished with design of block diagrams that represents crane model and motion, and gain results in form of diagrams containing main kinematic and dynamic parameters. Results of the tested system will be used to get conclusions about dynamic behavior of crane, and look for optimal motion control. Analysis will be done using modeling and simulations with software MapleSim, based on truck crane from standard manufacturer.

  • STUDYING ROTATIONAL MOTION OF LUFFING BOOM CRANES WITH MAXIMUM LOAD USING SIMULATIONS

    Machines. Technologies. Materials., Vol. 9 (2015), Issue 12, pg(s) 20-23

    Luffing Boom Cranes are type of cranes used for load carrying in building sites. They have complex structure with big dimensions and mechanisms. Their working usage is high. Main cycles of the work of Luffing Boom cranes are: lifting and lowering the working load, Boom luffing – upwards and downwards, rotation around vertical axes, and (if mobile type) translational movement forward and backwards. In this work, we are going to study the work of this crane while rotating with full loading. Study will be done using simulations with computer applications. The aim is to see the effects of dynamic forces and moments in the crane’s main parts – metal construction, cables, and constraints during rotational work cycle, particularly at the start and end of the rotation. Also interest is to study the effects of load swinging in crane’s stability. For this purpose, we modeled with software entire luffing boom crane. Crane is modeled from standard manufacturer, as a common model of luffing boom Crane.

  • INFLUENCE OF LOAD SWINGING ON DYNAMIC BEHAVIOR OF L-TYPE PORTAL CRANES DURING FORWARD TRAVELLING

    Machines. Technologies. Materials., Vol. 9 (2015), Issue 7, pg(s) 69-72

    Portal Cranes are used for load carrying in industrial and transportation sites. They have complex structure with big dimensions and many mechanisms with high security requests. In this work, we will study the influence of load swinging in dynamic behavior of Single girder L- type portal crane, in case of forward motion- travelling with full loading using computer modelling and simulations. Studying the behavior of portal cranes proves to be difficult using physical experimentation and measurement devices. Creating the crane’s computer model and applying simulations is useful method to study dynamic occurrences, which helps explaining the reasons of oscillations, failures and accidents of cranes, and gives conclusions that can be useful for design considerations and safety. The analysis will be concentrated in finding the nature of forces, moments and stresses that acts on crane’s construction and effects the stability, particularly at the start and end of travelling motion. Also, the study will look to find main parameters that contributes on the negative effects of load swinging. For this purpose, we designed “virtual portal crane” using model design and simulation applications. Crane is modeled from standard manufacturer, as a common model of L type portal cranes.

  • CONSERVING OF THE RESOURCES

    CRITICAL PERIOD METHOD – INNOVATIVE METHOD FOR SIZING OF THE IRRIGATION SYSTEMS: CASE KOSOVO

    Mechanization in Agriculture, Vol. 63 (2017), Issue 4, pg(s) 157-160

    Systematic approach and sustainable use of water and energy is the key point for human existence. Irrigation systems are one of the main directions for the development of the economy. Renewable energy sources, especially solar photovoltaic (PV) energy are suitable as input energy for the irrigation systems. By using the original and innovative scientifically sizing method named Critical Period Method, the irrigation systems are sustainable, given the economic, environmental and social indicators. This method includes design elements of the solution by subsystems: Photovoltaic generator + invertor – PV, pump station – PS and water reservoir – WR based on the critical period of operation of each one. Critical Period Method is different from the usual sizing methods because instead of a single critical period, which relates to the maximum daily water consumption, this method considers three critical periods (for subsystems PV, PS, and WR) due to the different balancing days. Each of the critical periods is determined with regards to a certain balance period. Critical day/period for subsystem PV is determined by statistical minimization, with regards to the difference between over pumped and demand quantity of water. For the subsystem, WR critical day/period is the day with maximum water demand and the shortest duration of solar radiation suitable for the operation of the pump station. A critical day/period for the subsystem PS also coincides with this critical day. Pumps use electric energy produced by using solar photovoltaic energy and causing water pumping into the water reservoir, which with its usual hydraulic role of storing water also has the function of energy reservoir. This concept is adaptable and can be implemented in the previously constructed systems, as well as for the new ones. Application of Critical Period Method replaces the installation of long energy supply lines and associated energy losses, and additionally reduces greenhouse gas emissions. Application of Critical Period Method is suitable for rural areas because of locations where classical power network is not available or has limited availability, i.e. remote areas and on islands. In order to prove this innovative method, a practical application is predicted to perform in irrigation of agriculture field in Deçan, Kosovo.