International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This paper deals with Dynamic analysis of Scissor Lifts during the Load Lifting to determine their dynamic behavior, find the nature of oscillations, and the regulation of lifting to minimize these oscillations and optimize the work process. During the motion processes, the lift and its main parts undergo heavy forces, moments, and oscillations. The method of research is acquiring results through design, modeling, and simulations, comparing them with analytic calculations, and looking for the optimal motion regulation of the Load Lifting. The analysis will be acquired when the Scissor lift is carrying maximum Load. The study will be concentrated in the finding the nature of dynamic forces and stresses that acts on the main parts of the lift and the extent and the form of oscillations. Results will be shown in the form of diagrams and contour views as the solution results of the tested system. Modeling and simulations will be carried using software SimWise 4D, based on the type of the Scissor Lift taken from Standard Manufacturer. Conclusions of these analyses are useful for design considerations, dynamic behavior, and safety of these types of lifts.

In the present paper, dynamic analysis of rigid four-bar linkage has been studied. Equation of motion has been obtained by using Lagrange’s Equation. Dynamic behavior of four-bar linkage has been analyzed using MATLAB/Simulink. Angular kinematics of each member of linkage have been determined.

This paper deals with dynamic analysis of bridge crane with one main girder during telpher motion in order to determine dynamic behavior and oscillations while carrying full load. During the telpher motion the main girders and side girders are heavy loaded parts while they undergo forces, moments and oscillations from lifting mechanism that carries workload. The method of analysis is the comparison of results gained through modeling and simulation and experimental measurements. The analysis will be concentrated in finding the nature of dynamic forces, moments and stresses that acts on main crane’s parts and finding the extent and form of oscillations that can cause damage and failures. Also the interest is to study the effects of load swinging in crane’s stability. Results will be shown in the form of diagrams as the solution results of the tested system. Crane is modeled from standard manufacturer, as a special type of Bridge Crane with one main girder and telpher. Conclusions of these analyses are useful for design considerations, dynamic behavior and safety.

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.

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%.

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.

Planetary gear systems are widely used in wind power systems because of the advantages of compact design, large carrying capacity, and high transmission efficiency. Despite these advantages, the several conditions under which such gears are typically used may lead to failure. Tooth pitting is one of the frequently encountered failure modes. The damage of teeth (as tooth pitting) is modeled for a wind turbine drive train. The drive train has got a three-stage gearbox that contains two high-speed parallel gear stages and a low-speed planetary gear stage. The proposed dynamic model of a wind turbine also includes a rotor and an electric generator. The model consists of 10 bodies and has got 11 degrees of freedom. The aerodynamic and generator torques are applied as external loads. The influence of tooth pitting on the gear mesh stiffness is scrutinized. Healthy drive train dynamic response and response of drive train containing tooth pitting are compared. The obtained results give an useful information about health monitoring of wind turbine drive train.