scholarly journals Improving the reliability of propulsion systems with a varying propeller thrust for ice-class vessels

2020 ◽  
Author(s):  
А.П. Сеньков ◽  
В.И. Кузнецов ◽  
Д.В. Никущенко ◽  
А.И. Фрумен
Keyword(s):  
Mechanical Strength ◽  
Structural Elements ◽  
Large Magnitude ◽  
Propulsion Systems ◽  
Mechanical Loads ◽  
Noise And Vibration ◽  
Fixed Part ◽  
Propeller Thrust

Пропульсивные системы на основе гребных электрических установок (ГЭУ) «Азипод» или винторулевых колонках (ВРК) позволяют изменять направление тяги гребного винта относительно корпуса судна, за счет чего обеспечивают судам высокую маневренность и повышают безопасность плавания. Движительный модуль ГЭУ «Азипод» и поворотная часть ВРК присоединяются к неподвижной части гребной установки, закрепленной на корпусе судна, как консоль, на опоре вращения. В результате опора вращения находится под воздействием целой системы сил и моментов большой величины, в том числе под воздействием ударов льдин при плавании во льдах. Высокие механические нагрузки на опору вращения снижают надежность пропульсивных установок на судах ледового класса, вызывают деформации элементов конструкции судов, увеличивают шумы и вибрации. Для повышения механической прочности и надежности гребной установки предлагается закрепить нижнюю часть движительного модуля ГЭУ «Азипод» или поворотной части ВРК во второй опоре вращения. Такая конструкция снизит нагрузки на верхнюю опору вращения, повысит механическую прочность и надежность гребной установки. Уменьшит шумы и вибрации. Propulsion systems based on Azipod propulsion systems or propeller-driven columns allow you to change the direction of propeller thrust relative to the hull of the vessel, thereby providing ships with high maneuverability and improving sailing safety. The Azipod propulsion module and the rotary part of the helical steering column are attached to the fixed part of the rowing installation, mounted on the hull of the vessel, like a console, on a rotation support. As a result, the rotation support is under the influence of a whole system of forces and moments of large magnitude, including under the influence of impacts of ice when swimming in ice. High mechanical loads on the rotation support reduce the reliability of propulsion systems on ice-class vessels, cause deformation of ship structural elements, and increase noise and vibration. To increase the mechanical strength and reliability of the rowing installation, it is proposed to fix the lower part of the Azipod propulsion module or the rotary part of the helical column in the second rotation support. This design will reduce the load on the upper support of rotation, increase the mechanical strength and reliability of the rowing installation. Reduce noise and vibration.

Technology for Utilization of Polymer Components of Municipal and Industrial Waste to Obtain Building Structures

2021 ◽  
Vol 25 (2) ◽  
pp. 4-7
Author(s):  
V.S. Ezhov ◽  
N.E. Semicheva ◽  
E.G. Pakhomovа ◽  
T.V. Polivanovа
Keyword(s):  
Mechanical Strength ◽  
Industrial Waste ◽  
Hot Water ◽  
Innovative Technology ◽  
Building Structures ◽  
Structural Elements ◽  
Fuel Gas ◽  
Polymer Component ◽  
Hot Water Supply ◽  
Strength And Durability

A brief substantiation of the proposed innovative technology for the utilization of polymer components of municipal and industrial waste with the receipt of elements of building structures is presented. Along with the utilization of polymers, the proposed technology provides for own utilization needs in fuel gas, as well as for the production of building structural elements and hot water for heating and hot water supply. The process of obtaining structural elements is accompanied by crystallization of their polymer component, which increases their mechanical strength and durability.

scholarly journals Creation of Polymer Coatings for Improving of Protective Properties of Surfaces

2021 ◽  
Vol 12 (2) ◽  
pp. 2698-2702
Author(s):  
A.A. Orekhov, Et. al.
Keyword(s):  
Mathematical Modeling ◽  
Mechanical Properties ◽  
Polymer Coatings ◽  
Strength Properties ◽  
Structural Elements ◽  
Properties Of Coatings ◽  
Mechanical Loads ◽  
Protective Properties ◽  
Modeling Methods ◽  
Metal Plates

In this paper, the preparation of polymer coatings on the surface of metal structural elements is considered to improve their physical, mechanical and strength properties. It is shown that the behavior of substrate samples under mechanical loads can be estimated using mathematical modeling methods. The properties of coatings and the mechanical properties of coated and uncoated metal plates have been evaluated. Methods for constructing mathematical models of metal plates of various structures are proposed.

scholarly journals About structural elements of polymer insulators of the contact network

2020 ◽  
Vol 79 (5) ◽  
pp. 310-316
Author(s):  
A. M. Luk’yanov ◽  
A. A. Luk’yanova
Keyword(s):  
Mechanical Strength ◽  
Electrical Strength ◽  
Contact Network ◽  
Critical Element ◽  
Structural Elements ◽  
Basic Principles ◽  
High Mechanical Strength ◽  
Low Weight ◽  
Polymer Insulators ◽  
The University

The high load on electrified lines makes tougher the requirements for the reliability and maintainability of power supply devices. Insulators are a critical element of the overhead contact network, and great attention is paid to improving their characteristics — electrical and mechanical strength. Advantages of polymer insulators in comparison with traditional ones made of porcelain and glass are generally recognized: manufacturability, low weight, compactness, ease of installation and transportation, high mechanical strength and shock resistance.The article presents the results of comprehensive studies of the electrophysical characteristics of fiberglass rods and bars made of AG-4S carried out by the University of Railway Engineers (MIIT), which were used in the developed polymer structures of the contact network. Recommendations are given on the maintenance of fiberglass rods and bars from AG-4S and their engineering support. The issues of the mechanical strength of polymer insulators of the overhead contact network are covered quite fully, therefore, this article offers the basic principles for calculating their electrical strength. The main requirements for modern polymer insulators and design features are briefly presented for each type: suspended, tension, cantilever, fixing and supporting.

Acoustic decoupling for structural elements by affixed supports - inherent contradiction or perfect complement? Restrained vibration isolation supports - a critical review

2021 ◽  
Vol 263 (4) ◽  
pp. 2801-2811
Author(s):  
Adam Wells ◽  
Patrick Carels
Keyword(s):  
Analytical Model ◽  
Critical Review ◽  
Laboratory Testing ◽  
Vibration Isolation ◽  
Mechanical Vibration ◽  
Structural Elements ◽  
Noise And Vibration ◽  
Vibration Isolators ◽  
Models Comparison ◽  
Isolation Performance

Restrained vibration isolation supports balance efficient isolation performance and stability for the supporting body under present loads. Necessary and beneficially for noise and vibration isolation applications with stringent stability requirements, such as full building isolation with potential uplift, interior partition sway bracing, curtain walls, elevator rail isolation, and mechanical vibration isolation, the performance of restrained vibration isolators are often misunderstood or oversimplified. This paper investigates the general vibration isolation theory used to create the analytical model for restrained isolation supports, intricacies of vibration isolation materials which may cause reality to diverge from well-known models, comparison of theory to laboratory testing, and a review of common uses/applications for these types of vibration isolation solutions, and recommendation to avoid undesired results from common pitfalls associated with restrained isolation supports implementation and installations.

THE METHOD OF SEQUENTIAL TRANSFORMATION OF THE SOUND FIELDS

Akustika ◽  
2021 ◽  
pp. 141
Author(s):  
Nickolay Ivanov ◽  
Gennady Kurtsev ◽  
Aleksandr Shashurin
Keyword(s):  
Noise Level ◽  
Sound Absorption ◽  
Sound Propagation ◽  
Sound Field ◽  
Structural Elements ◽  
Noise And Vibration ◽  
Main Assumption ◽  
Efficiency Calculation ◽  
Sound Fields ◽  
Sequential Transformation

A rule for describing the sequential transformation of the sound fields when properties of the surfaces or structural elements change due to such basic processes as sound absorption, reflection, diffraction, or sound divergence is proposed. The main assumption is that sound fields are non-coherent, i.e., resonant phenomena and sound interference are not considered. The examples show solutions to such problems: - sound propagation in space if there are artificial structures; - sound propagation in the rooms; - efficiency calculation of the noise protection structures; - calculation of the expected noise level of the machinery and separation of the contribution of noise and vibration sources to sound fields (for example, an external sound field, a sound field in the office, etc.)

Strength and Fractography of High Power Varistors

2005 ◽  
Vol 290 ◽  
pp. 358-365 ◽  
Author(s):  
Z. Wang ◽  
Peter Supancic ◽  
F. Aldrian ◽  
A. Schriener ◽  
Robert Danzer
Keyword(s):  
Field Strength ◽  
Mechanical Strength ◽  
Thermal Shock ◽  
Significant Role ◽  
Critical Field ◽  
High Power ◽  
Automotive Industry ◽  
Service Performance ◽  
Mechanical Loads ◽  
Inertia Effects

Electroceramic varistors, typically based on ZnO, show a strong non-linear currentvoltage characteristics. Actually they can be considered as electrical isolators below a critical field strength and highly conductive above. These components are used as over voltage protection elements in various fields of electric and automotive industry. In testing and in service high power varistors are loaded with µs-voltage pulses and suffer high mechanical loads due to thermal shock and inertia effects. Therefore the reliability in terms of mechanical strength becomes a crucial mark of quality. In this work the microstructure and the strength of commercial high power varistors of three different producers are presented. By a subsequent fractographic analysis fracture initiating defects are identified. It is shown, that defects in the microstructure, which result from the processing of the varistor components, play a significant role for the strength of the ceramics and of course also for the service performance of the components.

scholarly journals Redundancy as a Way Increasing Reliability of Ship Power Plants

2018 ◽  
Vol 1 (1) ◽  
pp. 515-522 ◽  
Author(s):  
Wieslaw Tarelko
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Structural Elements ◽  
Design Strategies ◽  
Propulsion Systems ◽  
High Level

Abstract One of key ways of assuring a high level of reliability of a ship power plant is to design redundancy of its structural elements, for example redundancy of prime drivers, drivelines etc. This paper deals with issues related to the redundancy as a way increasing dependability of the ship power and propulsion systems. Especially, fundamental characteristics of dependability, major design strategies influencing the reliability, and types of redundancies related to ship power and propulsion systems are presented.

scholarly journals Experimental studies of vibroacoustic characteristics of the basic structure parts of the traction rolling stock and transportation technological vehicles

2021 ◽  
Vol 2131 (2) ◽  
pp. 022045
Author(s):  
I Yaitskov ◽  
A Nazaretov ◽  
A Kochetkov
Keyword(s):  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Spectral Composition ◽  
Basic Structure ◽  
Internal Combustion ◽  
Rolling Stock ◽  
Combustion Engines ◽  
Structural Elements ◽  
Noise And Vibration ◽  
Railway Rolling Stock

Abstract The paper presents the obtained results of the vibration studies, particularly, the structural elements of the railway rolling stock, created at the driver workplaces, structures of the internal combustion engines, hoods, frames while moving and a stationary machine, which determine the vibration spectral composition and propose the specific engineering solutions for the noise and vibration protection system.

scholarly journals Laser Treatment for Strengthening of Thin Sheet Steel

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Oleksandr Kapustynskyi ◽  
Nikolaj Višniakov
Keyword(s):  
Mechanical Strength ◽  
Laser Treatment ◽  
Computer Simulations ◽  
Laser Processing ◽  
Sheet Steel ◽  
Thin Sheet ◽  
Experimental Studies ◽  
Structural Elements ◽  
Sheet Metal Parts ◽  
Thin Sheet Steel

This paper presents the results of computer simulations and experimental studies, aiming to increase the mechanical strength of sheet metal parts manufactured from high-quality structural carbon steel by means of local laser processing. The effects of laser processing on the strength of steel sheet plates and their ability to resist bend load after laser treatment were studied. The results of bending experiments and computer simulations of elastoplastic deformation establish that local laser processing with surface melting can be used to increase the mechanical strength of structural elements made from thin sheet steel C22E and to decrease its deflection under similar workload, as an alternative to the application of complex geometric shapes, additional strengthening elements, or heat treatment.

The Comparison of Methods of Testing Enameled Wire to Mechanical Stress

2015 ◽  
Vol 792 ◽  
pp. 33-37
Author(s):  
Andrey Leonov ◽  
Adelya Supueva
Keyword(s):  
Mechanical Strength ◽  
Mechanical Stress ◽  
Test Methods ◽  
Standard Test ◽  
Mechanical Resistance ◽  
Insulation Resistance ◽  
Comparison Of Methods ◽  
Test Results ◽  
Mechanical Loads

This work presents the test results of the enameled winding wires, characterizing an insulation mechanical strength. The standard and original test methods were used. It should be noted that the existing standard test methods do not estimate enamel insulation resistance to the mechanical loads authentically. Note that the estimation of wire mechanical resistance can be done by the determination of the number of defects in the enamel insulation. The results of tests for wires with various types of insulation are presented.

Sign in / Sign up

Export Citation Format

Share Document