Journal of Engineering Sciences / Журнал інженерних наук
Permanent URI for this collectionhttps://devessuir.sumdu.edu.ua/handle/123456789/34326
Browse
3 results
Search Results
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.