Journal of Engineering Sciences / Журнал інженерних наук
Permanent URI for this collectionhttps://devessuir.sumdu.edu.ua/handle/123456789/34326
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Item Mechanical properties and stress analysis of natural fiber reinforced polymer composite spur gear(Sumy State University, 2024) Jayaraj, M.; Ashok, S.K.; Thirumurugan, R.; Shanmugam, D.; Mahendran, M.This research study investigates the mechanical properties of polymer composites reinforced with natural fibers, specifically Palmyra palm leaf stalk fiber (PPLSF) and Palmyra palm primary leaf stalk fiber (PPFLSF). Tensile, flexural, and impact strength were among the composites’ mechanical parameters generated by integrating these fibers into a polymer matrix and assessing them experimentally. Additionally, stress analysis of a spur gear was conducted using the finite element analysis software ABAQUS. The composite material properties obtained from the experimental investigation were used in the analysis to evaluate the gear’s stress distribution and deformation behavior. The bending stress at the pitch point of the natural composite gears for PPLSF, PPFLSF, and nylon synthetic material is analyzed using analytical and experimental methods by ABAQUS software. Finally, the results are compared with each other. The results show that stress induced by nylon is comparatively higher than that of PPLSF and PPFLSF fiber. By analyzing these composites’ strength, durability, and stress distribution under operating environments, the study aims to determine whether they are suitable substitutes for conventional materials.Item Damage behavior of multilayer axisymmetric shells obtained by the FDM method(Sumy State University, 2024) Salenko, O.; Drahobetskyi, V.; Symonova, A.; Onishchenko, E.; Kostenko, A.; Tsurkan, D.; Vasiukov, D.This research rigorously explores the additive synthesis of structural components, focusing on unraveling the challenges and defect mechanisms intrinsic to the fused deposition modeling (FDM) process. Leveraging a comprehensive literature review and employing theoretical modeling and finite element analysis using ANSYS software, the study meticulously investigates the behavior of multilayer axisymmetric shells under varying internal pressure conditions. Critical parameters are identified, and the impact of design factors, including material properties, geometric parameters, and internal pressure, is quantitatively assessed using a rich digital dataset. In a series of model experiments, the study reveals specific numerical results that underscore the progressive nature of damage development in FDM-produced multilayer axisymmetric shells. Notably, under increasing internal pressure, stresses on the tank’s inner walls reach up to 27.5 MPa, emphasizing the critical importance of considering material properties in the design phase. The research also uncovers that the thickness of tank walls, while significant in resulting stresses, does not markedly impact the damage development mechanism. However, it places a premium on selecting rational parameters for the honeycomb system, including shell thickness, honeycomb height, honeycomb wall thickness, and honeycomb cell size, to minimize stress concentrations and enhance structural integrity. The inclusion of honeycomb structures in the tank design, as evidenced by specific results, provides enhanced thermal insulation properties. The research demonstrates that this design feature helps localize damage and mitigates the formation of significant trunk cracks, particularly along generative cracks.Item A novel force control strategy for improved surface integrity in low plasticity burnishing(Sumy State University, 2023) Livatyali, H.Ball burnishing is a cold work process where a hard ceramic or diamond ball rolls on a metal surface and flattens the roughness peaks under high local pressure. The small deformation created on the surface imposes compressive residual stresses and raises hardness in a shallow sub-surface layer, leading to improved fatigue, corrosion, and foreign object damage performances. Trial-and-error type experimental work to determine the optimum process parameters for a cold-forming process like ball burnishing for acceptable performance is costly. Therefore, the article aims to investigate the effects of various force control strategies in the double-sided low plasticity burnishing (LPB) process to find the effects on deformation and residual stresses on thin Ti6Al4V flat sheets. A 3D static-implicit finite element model was developed with an elastic-rigid plastic flow curve. Simulations were conducted to predict residual stresses and deformationі on the surface. As a result, it was proven that ball burnishing can produce a deterministically controlled surface. An increased vertical force produced higher deformation normal to the surface and, therefore, a deeper pool. As the ball proceeded further, a plowing effect developed such that when a 3.5–4.8 m deep pool was formed (at a vertical force of 150 N), a peak of 2.8 m was produced at the front end. Overall, the deformation on the surface and the residual stresses were directly interrelated. Parallel to the deformation on the surface, residual stresses on and beneath the surface also showed some variation. Nevertheless, the predicted residual stress variations were not big. They did not switch to the tensile mode in the burnished zone. Therefore, the whole sheet surface should be burnished to obtain all the compressive residual stresses.Item The stress state of a thick-walled hydraulic press cylinder with concentrators(Sumy State University, 2023) Lymarenko, A.; Kurgan, V.; Bazhanova, A.; Khamray, V.; Ponomarenko, A.; Karabegović, I.The article deals with modeling and calculations of volumetric machine-building structures with complex geometry. The relevance of the work lies in the fact that its methodology and results can help design massive structural elements complex in shape, including cylinders of powerful hydraulic presses. Attention is paid to the problems of reducing the metal content of machine-building products and the safe conditions of their operation. Theoretical and applied work is based on numerical methods using analytical solutions to assess the reliability of computer calculation results. The choice of research method is because analytical solutions for massive parts of such a configuration are too complex for numerical implementation. Experimental methods are too expensive and not so universal as to sort out possible variants of shapes and sizes. For the actual model of the press, the capabilities of the finite element method implemented in the ANSYS multipurpose complex were selected and rationally used. The results of the calculations are summarized in the table and shown on the graphs of the stress distribution. Based on the performed calculations (with a reliability check based on the formulas of the theory of elasticity for simplified calculation schemes), conclusions were made to ensure a more even distribution of stresses and a reduction in the metal content of the product.Item Rotor dynamics of turbocompressor based on the finite element analysis and parameter identification approach(Sumy State University, 2022) Вербовий, Антон Євгенович; Вербовой, Антон Евгеньевич; Verbovyi, Anton Yevhenovych; Хоменко, Владислав Володимирович; Хоменко, Владислав Владимирович; Khomenko, Vladyslav Volodymyrovych; Neamtu, C.; Pavlenko, V.; Симоновський, Віталій Іович; Симоновский, Виталий Иович; Symonovskyi, Vitalii Iovych; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan VolodymyrovychThe article is devoted to improving methods for designing a finite element model of rotor dynamics. For this purpose, numerical implementation of the authors’ computer program “Critical frequencies of the rotor” was developed based on the computer algebra system MathCAD. As a result of the scientific work, a refined mathematical model of rotor dynamics using finite beam elements was created. This model considers the dependence of the radial stiffness characteristics of the bearing supports on the values of the critical frequencies. The reliability of the mathematical model was justified by the permissible differences of the obtained results within 2% compared with the results of finite element analysis using the ANSYS software. The theorem was also proven by the mutual location of the spectra of the natural and critical frequencies. Overall, the proposed scientific approach reduces preparation and machine time compared to numerical modeling using the ANSYS software without losing the accuracy of the calculations.Item Mechanical behaviors of hybrid composites reinforced with epoxy resin(Sumy State University, 2021) Harikrishna, V.; Kumar, K.V.Natural fibres have emerged as a renewable and cheaper substitute to synthetic materials such as glass and carbon. A composite material can be defined as combining two or more materials that result in better properties. The constituents are reinforcement, and the other is a matrix. The main advantages of composites are high strength, stiffness combined with low density. As natural fibres are gaining more importance in recent times, many industries are focusing on these natural fibre composites, so that is why they are used as a component in composite materials. In this experiment, the analysis aims to characterize different natural fibres when combined with different ratios of the coconut coir and the bamboo. So, to fabricate the specimen, the hand lay-up method is used. The coconut coir and the bamboo composition are considered in three different variations. Then the natural fibres are subjected to resin and hardener compositions to test the suitability, tensile strength, flexural strength, and shore hardness test. We also conduct static analysis through ANSYS software.Item Design Optimization and Simulation Analysis of Formula SAE Frame Using Chromoly Steel(Sumy State University, 2019) Kumar, M.D.; Teja, P.S.; Krishna, R.; Sreenivasan, M.Відповідно до правил та правил змагань "Racing Formula Car Racing", що проводиться щорічно товариством інженерів-автомобілістів (Індія), рама автомобіля повинна бути розроблена та побудована з найвищим пріоритетом. Основним завданням є розробка та виготовлення легкої зваженої рами шасі автомобіля без втрати її надійності. У цій статті розглядаються різні методи вибору матеріалів та проведено процедуру оптимізаційного розрахунку конструкції рами на основі скінченноелементного аналізу за допомогою програмного комплексу ANSYS. Базова конструкція обгрунтована даними антропологічного дослідження зазначеної людини (водія) автомобіля. Відповідно до існуючих рекомендацій щодо вибору матеріалу, хромомолібденова стать 30ХМА була застосована для побудови рамної конструкції. У результаті, для остаточної конструкції рами транспортного засобу було виконано аналіз напружено-деформованого стану за допомогою програмного комплексу ANSYS, а отримані результати проаналізовані. Процедура оптимізаційного розрахунку конструкції рами грунтується на загальних правилах SAE 2019.Item Investigation of Non-linear Reactions in Rotors’ Bearing Supports of Turbo-pump Units for Liquid Rocket Engines(Sumy State University, 2018) Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Симоновський, Віталій Іович; Симоновский, Виталий Иович; Symonovskyi, Vitalii Iovych; Дем`яненко, Марина Миколаївна; Демьяненко, Марина Николаевна; Demianenko, Maryna Mykolaivna; Pitel’, J.; Verbovyi, A.Ye.This paper is aimed at refinement of the computational model of the turbopump rotor systems associated taking into consideration the effect of rotation of moving parts and compliance of bearing supports elements. The up-to-date approach for investigation of non-linear reactions in rotor’s bearing supports is proposed for turbo-pump units for liquid rocket engines. Five models for modelling contact interaction are investigated, and comparative bearing stiffness characteristics are given. The geometry of the housing and corresponding design scheme are set for each support due to the assembly drawing of the turbopump unit. Rotation of the shaft is taking into account by applying corresponding inertial forces to the inner cage of the bearing. Experimental points of the dependence “load – displacement” as the diagram “F – v” are built by the calculated points as an array of numerical simulation data, obtained by the ANSYS software. As a result of numerical simulation, including loading of the bearing support on the scheme “remote force” in a wide range of rotor speeds, the corresponding displacements are determined. The brandnew approach for evaluation of bearing stiffness coefficients is proposed based on the linear regression procedure. As a result, the obtained values of coefficients are summarized and approximated by the quadratic polynomials.