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

The paper examines a specific type of industrial elevator known as the hoist elevator that is used for lifting and lowering various materials. These elevators are used in various construction yards and usually are mounted close to the building being constructed. The elevator consists of many mechanical and electrical parts, and besides lifting and lowering the loads and the cage, it needs to stop at a certain height to unload. The vertical motion process is controlled by the operator on the ground. The work operation analyzed in this paper is load lifting from the ground up to a certain height. During this process, the elevator is heavily loaded, and oscillations will appear due to the lifting process. The type of analysis is dynamic analysis, and the methodology consists of 3D modeling of the elevator and carrying simulations with SimWise 4D software. This enables analysis of the lifting dynamics and identification of the nature and extent of forces, torques, and stresses on the elevator parts and the form and intensity of the oscillations. Results will be presented in graphical form and discussed. Conclusions from this study will be useful for motion dynamics, strength of elevator parts, and safety at work. The Hoist elevator is modeled based on the technical data from the manufacturer.

Cable-Stayed-Bridges are an important part of today’s constructions in the traffic infrastructure. New materials and computational technology have led to the construction of longer and slender Cable-Stayed-Bridges are under the effect of dynamic loads as wind, traffic or earthquakes. Besides comfort restrictions, the vibrations of large amplitudes effects also the lifetime of the entire structure. Oscillations of Cable-Stayed-Bridges can be reduced significantly by active damping systems. In this paper is represented shortly an electro-hydraulic actuator concept for the active damping of Cable-Stayed-Bridges. This type of control is very efficient even in large bridges (up to 900 m span). Also, the tests on a large-scale bridge show the efficiency of active damping in Cable-Stayed-Bridges using electro-hydraulic actuators. The damping of deck and cables, has become crucial in the design of cable-supported structures. Because of the effectiveness of passive damping systems is limited, this new electro-hydraulic actuator concept is developed.

This article is a study on the work operation of a hydraulic crane installed on a heavy truck known as Truck Loader Crane. The crane is used to carry loads from the truck to the ground and vice versa. It usually is an integral part of the truck mounted behind the cabin or behind the cargo body, and there are cases when it is additionally mounted on the truck. The crane has several mechanical and hydraulic parts. It is controlled from the command panel attached to the crane or by using the remote panel. The work operation analyzed is cargo unloading from the truck body on the ground. It is a complex process consisting of attaching the cargo (load) to the boom, lifting the cargo from the truck body, transferring the cargo several meters, and lowering it on the ground. During this process, the crane undergoes heavy oscillations due to the motion and swinging of the load it carries. The type of analysis is dynamic analysis, and the methodology consists of 3D modeling of the crane and implementing simulations with SimWise4D software. Through this study, the aim is to identify the nature and extent of forces and stresses on the crane and its parts, the intensity of the swinging and oscillations of the cargo, and their effect on crane operation. High oscillations can cause parts failure and raise concerns about safety. Results will be shown in graphical form for the main influential parameters. Conclusions from this paper will be useful regarding the strength of crane materials, motion dynamics and motion control of crane and cargo, design of crane parts and safety during work. The Truck Loader Crane model is designed based on the data from the standard manufacturer.

The paper examines the dynamic analysis of a hydraulic lift that is used for lifting and lowering vehicles. These lifts are implemented in various servicing facilities for the repair of vehicles. The lifts consist of various mechanical and hydraulic parts and besides lifting and lowering the vehicle, they need to keep the vehicle lifted for a certain amount of time. During the work operations, the lift’s main parts are heavily loaded. The method of analysis consists of 3D modeling of the Hydraulic lift and carrying simulations with software. This enables to analyze the dynamics of motion, identify the forces and stresses in lift parts and the form and intensity of oscillations that can cause failures of parts and concerns about the safety. Conclusions from this paper will be useful regarding the loading dynamics on the Hydraulic Lift during lifting and lowering, and design considerations. Results will be shown in graphical form, in time dependence. The Hydraulic Lift is modeled based on the Data from the standard manufacturer. The software that will be used for modelling and analysis is SimWise 4D.

Harvesting root crops still poses a challenging problem for the agricultural mechanization industry. Even though the technology of separate harvesting of tops and roots has undoubted advantages, the quality of the final product, i.e. roots, depends significantly on the accuracy of cutting tops from their heads to the roots and the thoroughness of their final cleaning from residues. One of the ways to solve this problem is to create improved constructions of peelers and their further testing, experimental and theoretical studies to determine their optimal structural and kinematic parameters. To implement the above, a new mathematical model was constructed, the study of which made it possible to assess the influence of the construction parameters of the root crop head cleaner from the residues of tops on the root on the indicators of its oscillatory process in the longitudinal-vertical plane when moving along uneven soil surfaces. Numerical calculations of the obtained mathematical model were carried out on a PC using the PTC Mathcad 15 software environment and the previously determined input numerical parameters. The amplitude-frequency and phase-frequency characteristics were constructed, which made it possible to determine the optimal parameters of this oscillatory system. Based on the mathematical modelling performed, the influence of irregularities in the longitudinal profile of the soil surface on the angular oscillations of the cleaner, as well as the influence of different values of the stiffness coefficient c and the damping coefficient μ of its two copy wheels, as well as the length l, or the longitudinal coordinate of their placement on the cleaner frame, was first of all determined. The mathematical modelling of the oscillatory movements of the cleaner made it possible to establish that the value of the stiffness coefficient c of the pneumatic tires of its trailing wheels should be not less than 315 kNm–1, which is ensured by the air pressure in its tires, which should be equal to 135 kPa. In addition, it has been established that the change in the value of the coefficient μ of damping of the tires of the cleaner’s tracking wheels should be in the following range 350…1350 Nsm–1 and this parameter does not affect the amplitude and phase frequency characteristics of oscillations under the influence of oscillations of the ordinates of the longitudinal profile of field surface irregularities in the frequency range 0…24 s–1. Also, the influence of oscillations of the longitudinal profile ordinates of the field in the specified frequency range of 0…24 s–1 depends little on the change in the value of the longitudinal coordinate l of the location of its tracing wheels. Therefore, the placement of the tracing wheels on the frame should be determined based on the constructional features of the cleaner.

In the article the calculated mathematical model of oscillations of the haulm-harvesting machine frontally attached to a wheeled tractor is constructed. A nonlinear differential equation is obtained, which describes the oscillations of a haulm-harvesting machine in the longitudinal-vertical plane during the movement of its pneumatic copying wheels along the unevenness of the soil surface. On the basis of the received theoretical results rational constructive and kinematic parameters of the front-mounted hoisting machine which provide decrease in amplitude of the specified fluctuations are defined. So, at translational speed of movement of the haulm-harvesting unit V = 3.0 m∙s–1, the amplitude of oscillations of the rotor of the haulm harvester decreases in 1.2…1.5 times in comparison with height of roughnesses of a surface of the field o h = ± 0.04 m. At the amplitude of oscillations of the lower ends of the knives of the rotary cutting device up to 4 cm, the loss of the tip does not increase significantly. However, when increasing the values of the amplitude of these oscillations to 7 cm or more, the loss of the branch increases significantly and the maximum values of which exceed 12%.

The paper presents dynamic analysis of the Semi-Portal Cranes for the case of Trolley motion travelling on Crane’s Girders. Semi-portal cranes are mainly mounted in the industrial facilities, and they consist of metallic structures with big dimensions and many mechanisms that carry heavy loads. We will analyze the influence of the Trolley motion in the dynamic behavior of Semi-Portal Crane while carrying maximum Load, in particular the influence of Load swinging and oscillations. The method of analysis is acquiring experimental measurements and comparing those results with the results gained through modeling of crane, and carrying simulations. Designing the Crane’s 3D model with software and motion simulations is the method applied in the paper to analyze dynamics and is important to explain the form and intensity of oscillations that can cause accidents, failures of parts, and other concerns about the safety. Analysis will be done for maximal and minimal speed of the Trolley. Conclusions from this paper will be useful about the design, dynamic response and safety of Semi-Portal Cranes. The analysis will be focused to find main kinematic and dynamic parameters influencing the crane dynamics, like forces, moments, speed (velocity), and Load swinging magnitude. The Crane is modeled based on the Data from standard manufacturer of Semi-Portal Cranes.

To establish influence of kinematic and constructive parameters of tops-harvesting machine on quality of a continuous cut of the massif of tops at oscillations in the longitudinal-vertical plane of its tops-cutting device at frontally mounted machine on a wheeled row-crop aggregate tractor. Used modeling methods based on higher mathematics, theoretical mechanics, solving a system of differential equations and compiling programs and numerical solutions on a PC. An equivalent scheme has been developed for a tops-harvester mounted on a wheeled tractor in front of it on its oscillations in the longitudinal-vertical plane, considering all the forces that arise, taking into account the kinematic excitation that occurs when moving along soil surface definitions also due to the elastic-damping properties of its support-copying wheels. For the specified equivalent scheme, on the basis of application of initial equations in the form of Lagrange of the 2nd kind, on the chosen generalized coordinates, the system of two nonlinear differential equations of oscillatory motion of the tops-harvesting machine is received. According to the analytical transformations, the solution of this system was obtained, which made it possible to obtain the f inal expressions for determining the amplitude and circular frequency of natural and forced oscillations of the tops-harvesting machine. Numerical calculations of the received expressions on the made program on the personal computer are carried out . According to the results of numerical simulation, the final expression was obtained, which allowed to determine the vertical displacements of the end of the rotary cutting unit during the oscillations of the topping machine in the longitudinal-vertical plane. Numerical calculations on the PC of the received expression gave the chance to construct graphic dependences which establish dependences of amplitude of the specified oscillations depending on constructive parameters of the tops-harvesting machine, and also characteristics of roughnesses of a soil surface and elasticdamping properties of copying wheels.

The operation of the machine attached to the back of the tractor to clean the heads of root crops from residues in the case of using copying pneumatic wheels causes oscillations of the tops harvester in the vertical plane, which significantly affects the quality of the process. Accordingly, the movement of the horizontal working body will depend on many structural and kinematic factors. Therefore, the development of a mathematical model that will describe the movement of the working body of such a unit is an important task. To solve which the method of construction of calculated mathematical models of functioning of agricultural machines and machine units, on the basis of theoretical mechanics and higher mathematics was used in the work.. Using which the equivalent scheme of movement of the unit is developed and the system of two nonlinear differential equations for detailed research of oscillations of the cleaner of heads of root crops in the longitudinalvertical plane at movement of its pneumatic copying wheels on roughnesses of a surface of soil is received. The mathematical model of movement of the cleaner with a horizontal cleaning shaft developed on the basis of initial equations of dynamics in the form of Lagrange of the 2nd kind allowed to establish depedencies between constructive and kinematic parameters of the car and its oscillatory characteristics. The found dependences created preconditions for the further mathematical modeling of parameters of the rear-mounted cleaner of heads of root crops, with a horizontal clearing shaft. Using the developed calculation model it is possible to optimize the values of angle B and coordinates у that characterize the oscillations of the machine in the longitudinal-vertical plane.

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.

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.

The main trend in considering the interaction of the railway track and the rolling stock is the studying of the parameters of the rigidity of the interaction. For the study, a model of the track design, described using the basic concepts of the theory of elasticity and the propagation of elastic waves was developed. The study of the peculiarities of the interaction of the rolling stock and the track, taking into account the elastic properties of the base, allows to expand the possibilities of solving the problems of ensuring their functionally safe operation with a certain level of operational efficiency.