Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines最新文献

{"title":"Three-frequency models for determining the orientation of a solid body taking into account the vibration environment","authors":"I. Homozkova","doi":"10.20998/2078-9130.2021.2.240771","DOIUrl":"https://doi.org/10.20998/2078-9130.2021.2.240771","url":null,"abstract":"Two new three-frequency reference models of solid motion taking into account the vibrational environment are proposed. They are based on a four-frequency reference model of rotation [1], which implements rotations according to Krylov angles. For the developed models the analytical dependences for quasi-coordinates, projections of the angular velocity vector and components of the quaternion of orientation corresponding to such rotational motion are obtained.\u0000The urgency of taking into account the influence of vibration in traffic modeling on the basis of domestic and foreign literature in the field of navigation, including for the last 10 years. The main sources of vibration are described in detail and what types of oscillations they correspond to - harmonic oscillations occur in moving elements of onboard systems, such as the engine rotor, and in the engine unit and its units there are oscillations that have the character of random broadband noise. Methods of correction of such influence for increase of accuracy of definition of orientation of object are analyzed. The location of the components of the platformless inertial navigation system relative to the vibration sources is considered to be related to the strength of the influence of the vibration environment on the accuracy of the obtained data.\u0000Numerical implementations of the models are obtained and the drift error for the third-order orientation algorithm is estimated for several sets of specified parameters in a certain way. The parameters are chosen arbitrarily, but taking into account the existing restrictions on angular motion. The corresponding figures show the result for one of these sets of numerical values (which shows the result of the research in the most detail). The obtained results are compared with the corresponding results for the four-frequency rotation model [1]. The expediency of using new three-frequency models under certain conditions is shown.","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123941377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Software tool for recognition of Ukrainian-language scientific articles","authors":"O. Tatarinova, V. Ovsyanikov","doi":"10.20998/2078-9130.2021.2.249715","DOIUrl":"https://doi.org/10.20998/2078-9130.2021.2.249715","url":null,"abstract":"The problem of computer recognition, both separately printed characters and whole texts, which may contain mathematical formulas, and further saving the resulting document in the \"Latex\" format, is considered. The developed software implements the ability to recognize printable Latin, Cyrillic, Greek letters and special mathematical symbols. For this, a multilayer convolutional neural network built using the Keras machine learning library and additional validation heuristics are used. To improve the quality of neural network recognition, a sophisticated image processing mechanism has been developed that helps to remove noise from the image, eliminate errors associated with the inclination of characters, and correct character defects associated with the quality of the input image. Also implemented are mechanisms for collecting individual characters into words or mathematical formulas, reproducing the position of signs of indices and degrees, forming ordinary fractions and expressions under the root sign. The results of the recognized text are saved in a file with the simultaneous construction of the \"latex\" document structure. To demonstrate the capabilities of the developed software, a graphical user interface has been added, with which you can select and inspect the input image even before the start of recognition. During testing of the software, the recognition of images of different types was carried out: completely textual, mathematical formulas without text, mathematical formulas that are between blocks of text.","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115851488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of two support spindle shaft on nonlinear elastic supports by rigidity characteristics","authors":"Sergij Yurijovich Pogorilov, Valerij Khavin, I. Khavina","doi":"10.20998/2078-9130.2021.2.242713","DOIUrl":"https://doi.org/10.20998/2078-9130.2021.2.242713","url":null,"abstract":"One of the main structural elements of metalworking machines is the spindle assembly (spindle), which is used to hold cutting tools or workpieces. The rigidity of the spindle assembly plays a decisive role in ensuring the accuracy and efficiency of the machine as a whole. The assessment of the spindle shaft stiffness is carried out on the basis of the analysis of the static bending of the spindle shaft, which made it possible to formulate and solve the problems of optimizing the spindle shaft according to the stiffness characteristics for two supporting structures on nonlinear elastic supports. To determine the stiffness of roller bearings, the work uses the dependence obtained on the basis of solving the problem of contact interaction of an elastic steel cylinder with curvilinear elastic steel half-spaces. For the considered design scheme, the optimization goals were chosen for the conditions of the smallest displacement of the end section of the spindle shaft console, the achievement of the minimum angle of rotation in this section or the minimum of their normalized superposition, which ensures maximum rigidity in the processing zone. Consideration has also been given to minimizing the swing angle at the front support to maximize bearing life. Mathematically, the problem is presented in the form of minimizing one of the 4 proposed objective functions by changing the variable parameters - the length of the cantilever and the value of the inter-support distance, represented as dimensionless quantities - the cantilever coefficient and the inter-support distance coefficient. Minimum and maximum values ​​of the cantilever length and shaft span were considered as constraints on the variable parameters. Varying the console coefficients and the inter-support distance was carried out by the method of sequential enumeration within the specified constraints, the solution of optimization problems is presented in a graphical form. The solution to the problem of shaft bending was carried out on the basis of the equation of the bent axis of the beam in the framework of the Euler - Bernoulli hypotheses and presented in an analytical form together with analytical dependencies for calculating the radial stiffness of a roller bearing as a function of the supporting force acting on it. The algorithm for solving optimization problems is implemented in the MatLAB package. Optimal solutions have shown that the minimum of the combined functions, consisting of the sum of the relative deflection values ​​at the end of the console and the angles of rotation at the end of the console and on the front support, is achieved at the same variable parameters as the minima of the angles of rotation at the end of the console and on the front support. The proposed approach to the design of the shafts of spindle units of metal-cutting machines, which are optimal in terms of rigidity characteristics, forms a tool for a reasonable choice of bearings and design parameters of spindle s","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116033987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear dynamic properties in curved laminated glasses","authors":"O. Sukhanova, Олексій Ларін","doi":"10.20998/2078-9130.2021.1.230161","DOIUrl":"https://doi.org/10.20998/2078-9130.2021.1.230161","url":null,"abstract":"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.","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"12 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121003051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lydia Kurpa - Outstanding Scientist Mathematician and Teacher (Dedicated to the Anniversary)","authors":"I. Morachkovska, G. Timchenko","doi":"10.20998/2078-9130.2019.2.190264","DOIUrl":"https://doi.org/10.20998/2078-9130.2019.2.190264","url":null,"abstract":"У статті міститься нарис про видатного вченого – математика та механіка, доктора технічних наук, професора Лідію Василівну Курпу. Наведено коротку біографію, описано педагогічні здібності, що виявились в її діяльності. Надано коротке викладення основних наукових результатів, що їх отримано Л. В. Курпою у різних розділах математики та механіки: методи теорії R-функцій, розв’язання початково-крайових задач теорії коливань, теорії пластин та оболонок. Наведено деякі науково-методичні праці, розроблені нею для студентів та викладачів на кафедрі прикладної математики Національного технічного університету «ХПІ».","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129249270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical solution of the elastic impact problem for a cone over a half-space","authors":"V. Olshanskiy, S. Olshanskiy","doi":"10.20998/2078-9130.2019.1.187416","DOIUrl":"https://doi.org/10.20998/2078-9130.2019.1.187416","url":null,"abstract":"","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127548575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of bulk cargo pressure on container stability during transportation by railroad ferry","authors":"A. Lovska","doi":"10.20998/2078-9130.2019.1.187413","DOIUrl":"https://doi.org/10.20998/2078-9130.2019.1.187413","url":null,"abstract":"Визначено тиск насипного вантажу на стіни контейнера при перевезенні у складі комбінованого поїзда на залізничному поромі. В якості розрахункового використаний метод Кулона з корегуванням Синельникова. Дослідження проведені стосовно контейнера типорозміру 1СС, завантаженого зерном. Враховано, що перевезення контейнера здійснюється на залізничному поромі «Герои Шипки», акваторією Чорного моря. При визначенні тиску враховано динамічне навантаження, яке діє на контейнер при коливаннях залізничного порому в умовах бортової хитавиці. При цьому розглянуто три схеми переміщень контейнера, розміщеного на вагоні-платформі при коливаннях залізничного порому: відсутність переміщень вагона-платформи та контейнерів відносно початкового положення при коливаннях залізничного порому (І схема); наявність переміщень вагона-платформи при коливаннях залізничного порому з урахуванням нерухомості контейнерів відносно рами вагонаплатформи (ІІ схема); наявність переміщень вагона-платформи відносно палуби та контейнерів відносно рами вагонаплатформи (ІІІ схема). Отримані результати враховано при визначенні стійкості контейнера відносно рами вагонаплатформи. Визначено кути крену залізничного порому при яких забезпечується стійкість контейнера відносно рами вагонаплатформи. Встановлено, що стійкість контейнера відносно рами вагона-платформи забезпечується при кутах крену залізничного порому – до 10° (І схема), до 8° – (ІІ схема), до 6° (ІІІ схема). Це викликає необхідність удосконалення схеми взаємодії контейнера з вагоном-платформою для забезпечення безпеки перевезень залізничним поромом. Проведені дослідження сприятимуть підвищенню безпеки перевезень контейнерів у складі комбінованих поїздів на залізничних поромах. Ключові слова: контейнер, навантаження конструкції, стійкість, комбінований транспорт, залізнично-поромні перевезення.","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123748190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the residual resource of the elements of construction of the pump of the energy installation on the basis of statistical assessment of total strenght","authors":"O. Larin, K. .. Potopalska, A. Chetverikova","doi":"10.20998/2078-9130.2019.2.190271","DOIUrl":"https://doi.org/10.20998/2078-9130.2019.2.190271","url":null,"abstract":"","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125258204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation of free oscillations of a dissipative oscillator with nonlinear elasticity","authors":"V. Olshanskiy","doi":"10.20998/2078-9130.2019.2.190273","DOIUrl":"https://doi.org/10.20998/2078-9130.2019.2.190273","url":null,"abstract":"Викладено наближений спосіб обчислення амплітуд вільних затухаючих коливань осцилятора, що має у виразі пружної характеристики нелінійний степеневий доданок, при дії сили лінійного в’язкого опору. Метод не потребує побудови розв’язку нелінійного диференціального рівняння руху і ґрунтується на відомому положенні по те, що обвідна графіка вільних затухаючих коливань дисипативного осцилятора Дуффінга наближено описується експоненціальною функцією, такою як і в лінійного осцилятора. Виходячи з цього положення, розрахунок амплітуд затухаючих коливань осцилятора зі степеневою нелінійністю в виразі пружності ,де є також лінійний доданок, зведено до рекурентних співвідношень. У випадку жорсткої силової характеристики в співвідношення входить двохзначна функція Ламберта від’ємного аргументу, де використана її перша гілка. Для м’якої силової характеристики рекурентне співвідношення має функцію Ламберта додатного аргументу, яка однозначна. З метою спрощення числової реалізації одержаних аналітичних розв’язків, рекомендовано використовувати відомі таблиці цієї спеціальної функції, а в випадку малих за модулем значень аргументу – запропоновану апроксимацію її елементарними функціями. Щоб надати інформацію про фактичні похибки запропонованого способу розрахунку, розглянуто приклади, де проведено порівняння результатів, до яких він призводить, з результатами числового комп’ютерного інтегрування диференціального рівняння руху осцилятора, для випадків квадратичної та кубічної нелінійностей. Задовільна узгодженість результатів порівняння підтвердила придатність використання запропонованого способу в інженерних розрахунках.","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116955081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variational formulation of the thermal deformation problems of electrically conductive bodies in an electromagnetic field","authors":"H. Altenbach, K. Naumenko, D. Lavinsky, V. Konkin","doi":"10.20998/2078-9130.2019.1.187409","DOIUrl":"https://doi.org/10.20998/2078-9130.2019.1.187409","url":null,"abstract":"The paper discusses issues concerning the thermal deformation of electrically conductive bodies under the action of the electromagnetic field. Similar problems arise, for example, in the analysis of induction heating processes. Transient electromagnetic field leads to heat release in electrically conductive bodies, and the change in temperature fields leads to a change of stress-strain state of a body. The creation of methods for the quantitative analysis of the stress-strain state of bodies under the action of an electromagnetic field is an urgent scientific problem because such an analysis allows us to evaluate the performance and durability of various structural elements. The modern approach dictates the need to consider three related problems: the problem of spatio-temporal distribution analysis of the electromagnetic field, transient heat-transfer problem and the problem of stress-strain analysis. The analysis of real technical and technological systems can only be done using appropriate numerical methods. In this case, the most universal is the finite element method, which has proven itself both in the analysis of the deformable bodies mechanics and in the analysis of various multiphysical problems. The usage of the finite element method requires an appropriate mathematical formulation of the problem. The mathematical problem formulation in variational form is considered in this article. Examples of corresponding functionals that allow finding solutions to a problem by finite element method are presented in the article. The functionals describing the transient distribution of the electromagnetic field are constructed based on the using of the concept of scalar electric and vector magnetic potentials. The influence of the electromagnetic field on the temperature distribution and the deformation process is taken into account by introducing distributed heat sources and distributed electromagnetic forces. The operation of varying the solution functions – potentials, temperature and displacements – makes it possible to obtain a system of resolving algebraic equations of the finite element method.","PeriodicalId":186064,"journal":{"name":"Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121194257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}