scholarly journals Discrete-continual mathematical models in solving vibration protection problems of building structures

2018 ◽  
Vol 212 ◽  
pp. 06003 ◽  
Author(s):  
Vladimir Sobolev
Keyword(s):  
Mathematical Models ◽  
Vibration Frequency ◽  
Dynamic Interaction ◽  
Technological Equipment ◽  
Building Structures ◽  
Load Bearing ◽  
Industrial Structures ◽  
Vibration Protection ◽  
Protection Systems

The paper outlines the method of forming mathematical models for the dynamic interaction of the vibroactive technological equipment with load-bearing structures of industrial structures on the basis of discrete-continual approximations previously developed by the author. Ways of implementing methods in the formation of vibration protection systems of structures are provided in the paper. The features of systems’ functioning and their sensitivity to fluctuating vibration frequency processes are also described.

Mathematical models for evaluating the effectiveness of shock-absorbing fasteners of vibro-active mechanisms of marine objects by vibrational power

2021 ◽  
pp. 13-20
Author(s):  
В.А. Пятакович ◽  
В.Ф. Рычкова ◽  
А.П. Пурденко
Keyword(s):  
Mathematical Models ◽  
Rational Design ◽  
Vibration Isolation ◽  
Vibrational Energy ◽  
Technical Problem ◽  
Vibration Protection ◽  
Protection Systems ◽  
Neural Network System ◽  
Theoretical Mechanics ◽  
Theoretical Developments

Для создания виброакустической защиты судового оборудования необходимо учитывать потоки колебательной энергии, распространяющиеся от источников как через опорные и неопорные связи, так и в виде воздушного шума. В работе представлены математические модели оценки эффективности амортизирующих креплений виброактивных механизмов морских объектов по колебательной мощности, учитываемые при обучении разрабатываемой нейросетевой системы классификации морских целей. Теоретические разработки в области виброзащиты и виброизоляции во многом имеют междисциплинарный характер и опираются на методы теории механизмов и машин, теоретической механики, теории колебаний, теории управления, используются методы инфорьт мационные технологии для оценки, поиска и выбора рациональных проектно-конструкторских решений. Создание амортизирующих устройств, способных защитить объекты от вибраций и ударов и, вместе с тем, обладающих ограниченными размерами, является сложной технической проблемой. В связи с этим первостепенное значение приобретают вопросы теории и расчета адаптивных виброзащитных систем. To create vibro-acoustic protection of ship equipment, it is necessary to take into account the flows of vibrational energy propagating from sources both through support and non-support connections, and in the form of air noise. The paper presents mathematical models for evaluating the effectiveness of shock-absorbing fasteners of vibro-active mechanisms of marine objects by vibrational power, which are taken into account when training the developed neural network system for classifying marine targets. Theoretical developments in the field of vibration protection and vibration isolation are largely interdisciplinary in nature and are based on the methods of the theory of mechanisms and machines, theoretical mechanics, vibration theory, control theory, information technology methods are used to evaluate, search and select rational design solutions. The creation of shock-absorbing devices that can protect objects from vibrations and shocks and, at the same time, have limited dimensions is a complex technical problem. In this regard, the issues of the theory and calculation of adaptive vibration protection systems are of paramount importance.

scholarly journals CPT Parameters of Loess Subsoil in Lublin Area

2021 ◽  
Vol 11 (13) ◽  
pp. 6020
Author(s):  
Krzysztof Nepelski ◽  
Agnieszka Lal
Keyword(s):  
Water Content ◽  
Building Structures ◽  
Load Bearing ◽  
Engineering Research ◽  
Loess Soils ◽  
Epigenetic Processes

Loess soils were created by the wind transporting particles with later or in parallel occurred protogenetic, syngenetic and epigenetic processes. As a result, various genetic processes affected loesses strength and deformability characteristics. The aim of the study is to estimate the main CPT parameters of loess subsoil in Lublin area according to divided facies. The subsoil in the area of the Nałęczowski Plateau, where Lublin is located, consists mainly of loess from aeolian and aeolian–diluvial facies, and in the deeper parts—from aeolian–alluvial facies. Most of the results obtained for the aeolian facies at the level of qc in the range from 4.5 to 8.0 MPa indicate that these soils are a good load-bearing substrate for building structures. Cone resistances mostly at the level of 1.5–4.0 MPa for the diluvial and alluvial facies confirm that these facies constitute less favorable foundation conditions. The reduced resistance results mainly from the increased water content in ground pores. It is especially the soils of the diluvial facies that provide unfavorable foundation conditions, as they occur near the surface. Genetic processes are a very important element that should be taken into account in engineering research.

scholarly journals Analysis of the natural oscillation frequency of the long-span trusses with flanged connections

2021 ◽  
pp. 76-85
Author(s):  
Татьяна Георгиевна Рытова ◽  
Людмила Анатольевна Максимова ◽  
Анастасия Георгиевна Николаева ◽  
Татьяна Михайловна Макарова ◽  
Надежда Георгиевна Пфаненштиль
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Frequency ◽  
Natural Vibration ◽  
Natural Oscillation ◽  
Natural Vibration Frequency ◽  
Building Structures ◽  
Long Span ◽  
Local Areas ◽  
Calculation Results ◽  
Natural Oscillation Frequency

Приводится анализ частоты собственных колебаний большепролетной фермы с фланцевыми соединениями. Выполнен расчет фланцевого соединения с различными случаями исключения болтов из работы соединения. Анализ результата расчета показал, что возникновение повреждений и дефектов конструкций здания в локальных зонах, величина которых несущественно снижает общую жесткость каркаса, практически не влияет на динамические характеристики каркаса. The analysis of the natural vibration frequency of a large-span truss with flanged connections is given. The calculation of the flange connection with various cases of exclusion of bolts from the connection operation is performed. Analysis of the calculation results showed that the occurrence of damage and defects in the building structures in local areas, the value of which significantly reduces the overall rigidity of the frame, practically does not affect the dynamic characteristics of the frame.

STRENGTHENING SUPPORTING COLUMNS WITH CARBON CONCRETE

2021 ◽  
Vol 95 (3) ◽  
pp. 59-67
Author(s):  
K. HOLSCHEMACHER ◽  
◽  
A.G. BULGAKOV ◽  
W. POLIENKO ◽  
◽  
...  
Keyword(s):  
Composite Material ◽  
Building Materials ◽  
Point Load ◽  
Geometrical Parameters ◽  
Building Structures ◽  
Technical School ◽  
Load Bearing ◽  
Floor Slabs ◽  
Wide Range ◽  
The Subject

Textile concrete is an innovative composite material that has been the subject of intensive research since the beginning of the 90s of the last century. After the approval of the rules and regulations on its application to strengthen floor slabs, an important step was taken towards its entry into the building materials market. Questions regarding the reinforcement of rod-shaped load-bearing elements of building structures need additional research. Despite the great potential available, the method of tying load-bearing supports and columns is still not well understood. There is a need for research on a wide range of geometric parameters and the reinforcement systems used. The Institute of Reinforced Concrete of the Higher Technical School in Leipzig tested various samples of carbon-reinforced samples in a wide range of geometrical parameters. Their goal was to assess the effect on a possible increase in the bearing capacity of carbon-reinforced columns at a concentrated point load.

VIBRATION PROTECTION SYSTEMS OF VEHICLES: ACTIVE CONTROL AND OPTIMIZATION

2021 ◽  
Vol 75 (4) ◽  
pp. 20-26
Author(s):  
Chernyshev Vladimir Ivanovich ◽  
◽  
Fominova Olga Vladimirovna ◽  
Gorin Andrey Vladimirovich ◽  
◽  
...  
Keyword(s):  
Active Control ◽  
Information Technologies ◽  
Control Function ◽  
Dynamic Properties ◽  
Singular Control ◽  
Vibration Protection ◽  
Protection Systems ◽  
Protective System ◽  
Link Information ◽  
Compensatory Effect

The article presents the results of studies of the dynamic properties of a vibration-protective system with active control, which is directly identified with the compensatory effect and is charac-terized as direct control, as well as a vibration-protective system with indirect control, which forms a compensatory effect mediated through the implementation of an intermittent process of changes in the parameters of the inertial link. To find the optimal positional control function of direct (ac-tive) control, as well as indirect (singular) control of the inertial link, information technologies for solving boundary value problems were used in relation to the canonical Hamilton equations for the vibration protection systems under study. The parameters are established at which vibration protection systems of this type eliminate resonance phenomena and provide comparable indicators of vibration safety for protected objects under kinematic disturbance.

The experimental study of glass multilayer columns using digital image correlation

2019 ◽  
Vol 1 (96) ◽  
pp. 32-41
Author(s):  
B. Demchyna ◽  
M. Surmai ◽  
R. Tkach
Keyword(s):  
Experimental Study ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
Building Structures ◽  
Load Bearing ◽  
Regulatory Documents ◽  
Triplex Glass ◽  
Calculation Methodology ◽  
Glass Columns

Purpose: The purpose of the research is to study the deformability of glass multilayer columns at the central compression using digital image correlation. It becomes possible to use the method of digital image correlation for the experimental study of load bearing building structures of glass. Design/methodology/approach: The approach which has been used to solve the above problems is to conduct an experimental study of glass columns on central compression, in which deformations were measured using digital image correlation. Findings: The possibility of using load bearing building structures of glass triplex has been discovered. A program of experimental studies was developed. It included the testing of prototype samples on central compression with rigid fastening. On the basis of the obtained results, a graph of dependence of relative deformations on normal tension, graphs of the dependence of the bending of columns on load in different planes, and a modulus of elasticity of triplex glass have been determined. Research limitations/implications: The lack of a calculation methodology and regulatory documents for designing load bearing building structures of triplex glass increases their cost, since each project is individual and requires the experimental research. Practical implications: Using the approaches developed in the paper, the method of digital image correlation, which is to measure deformations when testing glass structures on central compression can be applied. Originality/value: The experimental study is probably the first one in which deformations of glass columns are determined using the method of digital image correlation, so it is new and original. The lack of a calculation methodology and regulatory documents for designing load bearing building structures of triplex glass, increases their cost, since each project is individual and requires the experimental research.

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