Machine Science 2023 - Number II
Author: Amdulla MEKHRABOV, Ece A. IRMAK, M. Vedat AKDENİZ
Email: emdulla.mehrabov@aztu.edu.az
Abstract: The effects of particle size (2-6 nm) and temperature (300-1900 K) on the stability and local structural evolutions of amorphous bulk and nanoparticles of the FeNi3 alloys have been studied by using classical molecular dynamics (MD) simulation method combined with embedded atom model (EAM) in Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). The nanoparticles were obtained from the unstable amorphous bulk FeNi3 alloys. MD simulations have been performed for glassy FeNi3 intermetallic alloy by making use of pairwise interatomic interaction potentials and electron densities calculated via EAM method. The formation and evolution of structures and their stability have been analyzed at a wide temperature range (300-1900 K) by calculating radial distribution functions (RDF), interatomic distances (ID), coordination numbers (CN), core-to-surface concentration profiles, as well as Voronoi analysis. According to the results, although some deviations in the structural properties occurred during the heat treatment, the amorphous nanoparticles exhibited the same crystal structure and local atomic configuration with its bulk counterpart at room temperature.
Keywords: Fe-Ni, Amorphous, Bulk and Nanoparticles, Modelling and Simulations, Molecular dynamics, Embedded atom model
Author: Gökhan KIPER
Email: cavad.nacafli.v@aztu.edu.az, yadigarimam@gmail.com
Abstract: The method of decomposition is a useful method for function generation with multi-loop mechanisms. The recently introduced correction methods applied together with the method of decomposition allows the designer to cancel out the errors in the first loop of a two-loop mechanism with the errors in the second loop. In this study, the decomposition and correction method is applied for a Watt II type planar six-link mechanism with prismatic output. Five design parameters are defined for each loop resulting in ten design parameters in total. The design parameters are determined analytically. The generation error is decreased by adjusting free parameters such as the limits of the some joint angles and parameters due to the decomposition of the function to be generated, while considering several constraints such as link lengths ratios and ranges of the joint variables. The success of the method is illustrated with a numerical example.
Keywords: Function generation, decomposition and correction method, planar Watt II mechanism with prismatic output
Author: Beyali AHMEDOV, Isa KHALILOV, Anar HAJIYEV
Email: ahmedov.beyali@mail.ru, khalilov@aztu.edu.az, anar_hajiyev_1991@mail.ru
Abstract: As is known, in world, oil production is carried out both in the sea and in oil fields on land. For the mechanized exploitation of oil fields on land, in most cases used different type of sucker-rod pumps. The main object of the study of the article is a new constructive solution of the pumping unit, the novelty of which is approved by the ownership certificates. The main factor characterizing the operation of pumping units is its quality indicators such as metal consumption, reliability, efficiency and energy consumption. When switching from a balanced sucker-rod pumping unit to an unbalanced the efficiency factor decreases from 0.834 to 0.65 and the operating power factor decreases from 0.605 to 0.312. In this case, power losses increase sharply not only in transmissions, but also in energy distribution networks. If the engine is not fully loaded or is not selected correctly, then these energy coefficients decrease even more. The selection of engine power is performed according to the worst conditions, i.e. the cyclic mode of operation of an unbalanced pumping unit. Despite this, it can be said that in almost all oil fields, the power of asynchronous motors is greatly exaggerated, which causes additional losses. In article proposed expressions for determining the optimal power of the electric motor were proposed, taking into account the efficiency factor of the balancing device during the balancing of the proposed new constructive solution of the beamless pumping unit with a combined, movable counter weights and rotary counter weights. This allows to prevent excess energy consumption and reduce energy costs. Which is very important in the era of globalization, when energy prices are rising sharply.
Keywords: oil, pumping unit, efficiency, balancing, electric motor
Author: Ke XU, Huiping SHEN, Jiaming DENG, Yunyu SHEN
Email: 1375928645@qq.com, shp65@126.com, czdydjm@126.com, 919304858@qq.com
Abstract: The typical 3-RRR planar parallel manipulator with two translations and one rotation has extensive applications such as plane location and motion transfer. But it suffers two disadvantages. One is its analytical direct kinematics is difficult to be got and another is not input-output motion decoupled. This paper focuses on its topological structure optimization and resulting kinematic performance improvementt. First, the coupling degree of this manipulator is calculated being k=1. Second, based on structure coupling-reducing principle, its coupling-reduced manipulator with zero coupling degree is designed, which not only leads to be easy to get its analytic direct kinematic solutions, but also makes input-output motion partially decoupled. Moreover, based on workspace and singularity of this coupling-reduced manipulator, comprehensive comparison of two manipulators before and after coupling-reducing showed that the main performances of structure coupling-reduced manipulator are superior than that of the typical mechanism. The work shows that structure coupling-reducing is effective method for optimization of topology structure.
Keywords: parallel mechanism, direct kinematics, structure coupling-reducing, performance analysis
Author: Mario MÜLLER, Esther HÖRTER, Mathias HÜSING, Burkhard CORVES
Email: mueller@igm.rwth-aachen.de
Abstract: The combination of the established synthesis methods for finite positions and path-points leads to a hybrid dimensional synthesis method that is presented within this paper. This hybrid method combines the advantages of the established synthesis methods so that an adjustable definition of a synthesis task as well as a high performance of the algorithm can be ensured. To realize this combination, the established algorithms have to be modified as shown within this paper. Depending on the synthesis task and its degree of freedom, a solution can be found analytically or numerically. Both of these algorithms as well as the algorithm for the calculation of the synthesis degree of freedom is treated in this contribution. The shown approaches are validated by two examples.
Keywords: Dimensional Synthesis, Planar Mechanisms, Finite Position, Path-Point
Author: Iftikhar CHALABI
Abstract: Violation of the density between the housing and the cover of gear reducers can lead to gaps, noise and impacts from gear engagement, an increase in the load on the teeth, and in many cases, to their failure. Therefore, the presented report assessed the reliability of bolted connection connecting the housing and the cover of parallel-shaft reducers according to various failure criteria. It was found that the probability of a violation of the density between the parts is many times higher than the probability of loss of bolt strength.
Keywords: parallel-shaft reducers, reliability, threaded connections, endurance, joint density
Author: Metanet MEHRABOVA, Amdulla MEKHRABOV
Email: metanet.mehrabova@aztu.edu.az, emdulla.mehrabov@aztu.edu.az
Keywords: AIIBVI compounds, CdMnTe, electrical and photoelectrical properties, γ-ray irradiation
Author: Javad NAJAFLI, Yadigar IMAMVERDIYEV
Email: cavad.nacafli.v@aztu.edu.az, yadigarimam@gmail.com
Abstract: Solar panels, as an important source of renewable energy, are exposed to external factors such as dust accumulation and environmental pollution, which reduces their efficiency. To ensure timely cleaning of panels from contamination, monitoring of their condition is required. Monitoring can be carried out directly by a person or using visual detectors. This paper examines the second case, namely the use of AI to assess panel contamination. The AI used to assess the condition of the panels may be trained on images captured by cameras with a different resolution than the surveillance system in which it is embedded, which may result in the AI's inability to produce results under new conditions. This work evaluates the impact of changing the quality of images processed by AI on its effectiveness. To do this, a CNN (Convolutional Neural Network) model was used and a set of images of clean and dirty solar panels was taken, followed by their separation by resolution. The model was trained on a set of images of one quality and tested on others, and this approach was applied for each resolution. As results were obtained, elements from other sets were added to each set to stabilize the training of the neural network. During the work, the importance of using images of different qualities for training a neural network was assessed, as well as the minimum set to prevent overtraining due to the lack of quality differences. Taking into account the results obtained, it is possible to prevent the creation of inflexible neural networks, as well as save on using the minimum required data to stabilize training.
Keywords: CNN; solar panels; green energy; artificial intelligence; contamination detection
