Bending of a ship's skin panel loaded along the axis of symmetry

Задача изгиба прямоугольной панели обшивки от действия распределенной по оси симметрии поперечной нагрузки не имеет точного решения в конечном виде в виду сложности краевых условий и вида нагрузки. Использование другими авторами различных приближенных методов оставляет открытым вопрос о точности полученных результатов. Целью исследования является получение точного решения с помощью гиперболо-тригонометрических рядов по двум координатам. Для этого используется метод бесконечной суперпозиции указанных рядов, которые в отдельности удовлетворят лишь части граничных условий. Порождаемые ими невязки взаимно компенсируются в ходе итерационного процесса и стремятся к нулю. Частное решения представлено двойным рядом Фурье. Точное решение достигается увеличением количества членов в рядах и числа итераций. При достижении заданной точности процесс прекращается. Получены численные результаты для прогибов и изгибающих моментов для квадратной пластины при различной длине загруженной части оси пластины. Представлены 3D-формы изогнутой поверхности пластины и эпюры изгибающих моментов. The problem of bending a rectangular skin panel from the action of a transverse load distributed along the axis of symmetry does not have an exact solution in the final form due to the complexity of the boundary conditions and the type of load. The use of various approximate methods by other authors leaves open the question of the accuracy of the results obtained. The aim of the study is to obtain an exact solution using hyperbolo-trigonometric series in two coordinates. To do this, we use the method of infinite superposition of these series, which individually satisfy only part of the boundary conditions. The residuals generated by them are mutually compensated during the iterative process and tend to zero. The quotient of the solution is represented by a double Fourier series. The exact solution is achieved by increasing the number of terms in the series and the number of iterations. When the specified accuracy is reached, the process stops. Numerical results are obtained for deflections and bending moments for a square plate with different lengths of the loaded part of the plate axis. 3D shapes of the curved surface of the plate and diagrams of bending moments are presented.

The Dynamic and Strength Analysis of an Articulated Covered Wagon with the Circular Pipe Design

An articulated covered wagon design was developed. The wagon feature is that the body-bearing elements are made of circular pipes. This technical solution made it possible to reduce the tare weight of the wagon while ensuring the strength conditions. Mathematical simulation of the dynamic loading of the developed articulated covered wagon design was carried out under the main operating conditions. In the calculations of the observed quantities, an application of symmetry with regard to the longitudinal axis of the wagon was used. The accelerations, as the components of the dynamic load acting on the wagon, were determined. The dynamic loading computer simulation results of the developed wagon design are also presented. The strength analysis of the articulated covered wagon supporting structure made it possible to conclude that the strength indexes were within the allowed limits. The wagon bearing structure was analyzed for fatigue strength. The weld strength analysis results of the most loaded part of the wagon-bearing structure are presented. The results obtained for the desired quantities revealed their symmetrical distribution in the wagon structure. This research will contribute to improving the efficiency of railway transport operation.

Analysis of speech MEL scale and its classification as big data by parameterized KNN

Recognizing emotions and human speech has always been an exciting challenge for scientists. In our work the parameterization of the vector is obtained and realized from the sentence divided into the containing emotional-informational part and the informational part is effectively applied. The expressiveness of human speech is improved by the emotion it conveys. There are several characteristics and features of speech that differentiate it among utterances, i.e. various prosodic features like pitch, timbre, loudness and vocal tone which categorize speech into several emotions. They were supplemented by us with a new classification feature of speech, which consists in dividing a sentence into an emotionally loaded part of the sentence and a part that carries only informational load. Therefore, the sample speech is changed when it is subjected to various emotional environments. As the identification of the speaker’s emotional states can be done based on the Mel scale, MFCC is one such variant to study the emotional aspects of a speaker’s utterances. In this work, we implement a model to identify several emotional states from MFCC for two datasets, classify emotions for them on the basis of MFCC features and give the correspondent comparison of them. Overall, this work implements the classification model based on dataset minimization that is done by taking the mean of features for the improvement of the classification accuracy rate in different machine learning algorithms. In addition to the static analysis of the author's tonal portrait, which is used in particular in MFFC, we propose a new method for the dynamic analysis of the phrase in processing and studying as a new linguistic-emotional entity pronounced by the same author. Due to the ranking by the importance of the MEL scale features, we are able to parameterize the vectors coordinates be processed by the parametrized KNN method. Language recognition is a multi-level task of pattern recognition. Here acoustic signals are analyzed and structured in a hierarchy of structural elements, words, phrases and sentences. Each level of such a hierarchy may provide some temporal constants: possible word sequences or known types of pronunciation that reduce the number of recognition errors at a lower level. An analysis of voice and speech dynamics is appropriate for improving the quality of human perception and the formation of human speech by a machine and is within the capabilities of artificial intelligence. Emotion results can be widely applied in e-learning platforms, vehicle on-board systems, medicine, etc

HIGH STRENGTH STRUCTURAL STEELS FOR GAS-TURBINE ENGINE SHAFTS (review)

The motor shaft of a gas turbine engine, being a highly loaded part of a particularly critical purpose, has increased requirements for maintaining the level of properties during long-term operation, ensuring the structural strength of the product. An increase in the resource and durability of the product is achieved due to the development of new materials that surpass the used domestic and foreign analogues in their mechanical characteristics. FSUE «VIAM» has deve-loped high-strength structural steels with enhanced characteristics of strength, toughness, durability and heat resistance.

Big Data Classification for the Analysis MEL Scale Features Using KNN Parameterization

The role of human speech is intensified by the emotion it conveys. The parameterization of the vector obtained from the sentence divided into the containing emotional-informational part and the informational part is effectively applied. There are several characteristics and features of speech that differentiate it among utterances, i.e. various prosodic features like pitch, timbre, loudness and vocal tone which categorize speech into several emotions. They were supplemented by us with a new classification feature of speech, which consists in dividing a sentence into an emotionally loaded part of the sentence and a part that carries only informational load. Therefore, the sample speech is changed when it is subjected to various emotional environments. As the identification of the speaker’s emotional states can be done based on the Mel scale, MFCC is one such variant to study the emotional aspects of a speaker’s utterances. In this work, we implement a model to identify several emotional states from MFCC for two datasets, classify emotions for them on the basis of MFCC features and give the comparison of both. Overall, this work implements the classification model based on dataset minimization that is done by taking the mean of features for the improvement of the classification accuracy rate in different machine learning algorithms.

Design of a robotic manipulator for handling products of automotive industry

Automation is a process of handling and transport of products, which allows replacing man’s control by operation of manipulators and robots. It represents a highly complex process, which includes several operations and they are usually performed automatically by particular devices. In this article, a technical design of a universal versatile robotic manipulator for handling with automotive products is presented. The designed device is intended for handling with automotive products with a maximum weight of 25 kg. The technical solution of the manipulator comes from required specifications and operation conditions given by the customer, who will install it as a part of an automatic line. A particularity of the manipulator is the special functionality, which allows handling with objects of both circular and angular shapes. This is ensured by adaptable gripping fingers, which are able to adjust their position by means of a well-considered mechanism. The technical design of the manipulator includes calculation of forces needed for reliable gripping of manipulated objects, choice of a working screw and calculation of the load and carrying out of strength analyses of the main loaded part of the manipulator. Based on results, there is recommended an appropriate material for the manufacture of the device to reach its optimal accuracy of positioning of handled objects during a long-term operation.

Metal to Composite Plastic Conversion of Mechanically Loaded Part Using Numerical CAE Analyses

The material replacement of component is often used procedure, which helps to reduce production costs, simplify manufacturing, improve functional properties of component and bring another benefits. In the last years, more and more metal parts are converted to plastic, also in the cases of mechanically loaded parts. For these special applications, the fibre reinforced composite plastics are successfully used. However, the mechanical properties of composite plastic are strongly dependent on the fibres orientation and following anisotropic behaviour. Moreover, the orientation of fibres is influenced by the conditions of the part production. Due to the number of these dependencies, the material conversion becomes a complex task which cannot be solved with analytical approach. Especially in case of complicated part geometry. In this study, the connection of two different numerical solvers was used for material conversion of a part from automotive industry. First, the new geometry of analyzed part was designed in order to compensate lower mechanical properties of plastic in comparison to metal. Next, the new part manufacturing was simulated and this way obtained anisotropic properties of composite plastic were described. Finally, the structural analyses of original metal and new composite plastic part with real anisotropic properties were performed to verify achievement of material conversion. The aim of this study is to demonstrate, how numerical analyses can help to predict an unexpected result.

Assessment of Reliability and Overall Life-Time of the Turbo Generator in the Kamýk Power Station

This paper presents the results of measurement of the stress and the theoretical analysis of the steel structure of the Kaplan turbo generator in the Kamýk power station in the Czech Republic. Based on the number of load cycles and the finding of the maximum stress range of critical details of the most loaded part, the lower star, the residual lifetime of the turbo generator was determined.

Assessment of Reliability and Overall Life-Time of the Turbo Generator in the Lipno Power Station

This paper presents the results of visual inspection and the theoretical analysis of steel structure of the upper star of the Kaplan turbo generator in the Lipno power station in the Czech Republic. Based on the number of load cycles and the finding of the maximum stress range of critical details of the most loaded part, the upper star, the residual life-time of the turbo generator was determined.