Вісники НТУ "ХПІ"

Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/2494


З 1961 р. у ХПІ видається збірник наукових праць "Вісник Харківського політехнічного інституту".
Згідно до наказу ректора № 158-1 від 07.05.2001 року "Про упорядкування видання вісника НТУ "ХПІ", збірник був перейменований у Вісник Національного Технічного Університету "ХПІ".
Вісник Національного технічного університету "Харківський політехнічний інститут" включено до переліку спеціалізованих видань ВАК України і виходить по серіях, що відображають наукові напрямки діяльності вчених університету та потенційних здобувачів вчених ступенів та звань.
Зараз налічується 30 діючих тематичних редколегій. Вісник друкує статті як співробітників НТУ "ХПІ", так і статті авторів інших наукових закладів України та зарубіжжя, які представлені у даному розділі.

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2019 - 201912020 - 20222

Налаштування

Автор: search.filters.author.Larin, Oleksiy Oleksandrovych

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Зараз показуємо 1 - 3 з 3
  • Ескіз
    Публікація
    Computer modeling of the stress state and reliability assessment of bolted connections of the rotor and runner of kaplan turbines
    (Національний технічний університет "Харківський політехнічний інститут", 2022) Vodka, Oleksii O.; Viazovychenko, Y. A.; Larin, Oleksiy Oleksandrovych; Potopalska, K. E.
    This study presents a comprehensive theoretical assessment of the deformed state and stresses in the bolted joints of the runner and shaft of the hydroturbine. The investigation is motivated by the need to understand the structural behavior of these critical components under varying operational conditions. The primary purpose of this research is to evaluate the theoretical aspects of the bolted joints hydro-turbine, emphasizing the impact of tightening technology on the deformed state and stress distribution. A comprehensive review of literature, drawings, material properties, and acting loads of the bolted connection for turbines is conducted, estimating loads during normal operation and load rejection. A detailed nonlinear finite element model of the bolted joint is built, considering a 3D bolt model and runner fragments. The model incorporates nonlinear effects such as contact interaction and plasticity of the material during deformation. A methodology for modeling bolted joint tightening technology is developed, allowing estimation of bolt pre-operation stress and deformed states. Error estimation and model validation are performed through a comparative analysis of models with different meshes. Stresses arising at different tightening levels are determined, showcasing the non-linear effect on bolt stresses. The study reveals that the maximum numerical error in stress estimation does not exceed 5.2%. Stresses at different tightening levels demonstrate a nonlinear response, with significant reductions and increases corresponding to tightening deviations. Estimated stresses in the main operating loading cycle provide insights into the amplitude and average stress values during normal operation and load rejection. The study estimates a significant number of cycles before the initiation of a fatigue crack, equivalent to approximately 142 years of operation.
  • Ескіз
    Документ
    Linear dynamic properties in curved laminated glasses
    (Національний технічний університет "Харківський політехнічний інститут", 2021) Sukhanova, Olha Ihorivna; Larin, Oleksiy Oleksandrovych
    The study presents the results of linear dynamics of laminated glass panels with different curvatures. This is an actual task in the field of mechanical engineering, aviation, shipbuilding, energy, architecture, etc. Such composites are durable, easy to care for and have a wide range of design options. The aim of the work is to study the influence of the curvature parameter on the frequencies and modes of composites. The paper considers the linear characteristics for laminated glass with polyvinyl butyral interlayer. The article considers behavior of the triplex and the propagation of elastic waves in the linear state. The paper performs calculations using the finite element method in the framework of modal analysis in a three-dimensional formulation in the framework of a physical linear-elastic formulation. The study uses hexagonal finite element with 8 nodes with 3 degrees of freedom in each. This work model laminated glass with a curvature parameter ranging from 0 mm to 250 mm. The composite consisted of three layers: two glass layers thickness of each was 3 mm, and a polyvinyl butyral interlayer with 0.38 mm thickness. The size of the plates was 500×500 mm. As a boundary condition, the laminate was fixed on two opposite sides. The article performs mesh size convergence analysis. The results of natural frequencies in accordance with the curvature parameter are derived. The graphs of natural vibration modes are also shown, that give a clear view about the state of composites.
  • Ескіз
    Документ
    Simple shear: eigenvectors of Сauchy-Green tensors rotate against each other
    (Національний технічний університет "Харківський політехнічний інститут", 2019) Itskov, Mikhail; Larin, Oleksiy Oleksandrovych
    Simple shear represents a somewhat complex case of deformation although it is very good studied. In this paper, we discuss a new aspect of simple shear which has not been observed before. Rotations of the eigenvectors of the right and left Cauchy-Green tensors with increasing amount of shear under the kinematically defined simple shear are theoretically studied. An analysis has been done within a framework of the nonlineartheory of elasticity. Mathematical processor Maple is used for the calculations and animation of the results. Phenomena of mutually opposite rotations of the eigenvectors of the right and left Cauchy-Green tensors is fond that can be important for anisotropic and in particular fibre-reinforced materials. We studied rotations of principal strain directions under the kinematically defined simple shear. Accordingly, eigenvectors of the right and left Cauchy-Green tensors rotate against each other with the increasing amount of shear. Interestingly, the eigenvectors of brotate in the same direction as line elements of the material while the eigenvectors of Cin the opposite direction. For example, this can be important for anisotropic and in particular fiber rein-forced materials. In this case, the direction of the maximal stretch will rotate with respect to reinforcement directions.