scholarly journals Измерение напряженно-деформированного состояния деталей АГТД методом тензометрии

2021 ◽  
pp. 44-51
Author(s):  
Сергей Сергеевич Крыгин ◽  
Юрий Иванович Торба
Keyword(s):  
Strain Gauge ◽  
Electromagnetic Interference ◽  
Strain State ◽  
Total Error ◽  
Current Collector ◽  
Measuring Channel ◽  
Recording Equipment ◽  
Stress Strain ◽  
Advantages And Disadvantages ◽  
Stress Strain State

The subject of study in the article is various methods of measuring the stress-strain state of AGTE parts by the tensometry method. Differences were revealed when measuring the stress-strain state of rotor and stator parts, in different frequency ranges (study of static, static-dynamic and dynamic deformations). Methods for compensating or reducing the influence of external factors on the measurement results, such as temperature changes and electromagnetic interference, are indicated. The aim is to develop recommendations for research of AGTE parts in a test bench in a gradient of varying temperatures and in a complex electromagnetic environment of the engine. A review of the sources of inaccuracies, errors and interference arising during preparation for testing and directly during the measurement of the SDS of AGTE parts is performed. The effects of wiring, cabling, grounding and shielding can not only increase the level of errors, but can also negate the advantages of an expensive and extremely reliable electronic part of the system. The advantages and disadvantages of the most common schemes for connecting strain gages, as well as their areas of application are presented. Possible ways to compensate for imaginary deformations at temperatures outside the range of thermal compensation of primary converters. A list of common strain gauge systems with their advantages and disadvantages is given for each type of parts and frequency ranges of measurements. When strain measurement rotary parts to output the signal from the strain gauge to recording equipment used various current collector. The possibility of using wireless interfaces for communication between the primary converter and the recording equipment is also indicated. The described methods are: ways to compensate for imaginary deformations caused by changes in the temperature of the investigated part and connecting wires. Elimination or minimization of electromagnetic interference on the measuring channel. An estimate is given of the total error in measuring the deformation for a particular object under study for the final loading cycle, the specificity of the bench strain gauge path, the errors of the current collector in bench conditions, and others in the process of static strain gauging.

scholarly journals ОПТИМІЗАЦІЯ ВИМІРЮВАЛЬНИХ ЗАСОБІВ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ ЗА ДОПОМОГОЮ ТЕНЗОДАТЧИКІВ

2019 ◽  
pp. 50-56
Author(s):  
Людмила Володимирівна Кузьмич ◽  
Дмитро Петрович Орнатський ◽  
Володимир Павлович Квасніков
Keyword(s):  
Strain Gauge ◽  
Strain State ◽  
Approximation Error ◽  
Strain Gauges ◽  
Mean Square ◽  
Stress Strain ◽  
Stress Strain State ◽  
Destabilizing Factors ◽  
Mechanical Factors ◽  
The Mean

In the article, the principles of construction, design and mathematical modeling of deformation and stresses of complex technical constructions are developed with the help of strain gauges and strain gauges taking into account destabilizing factors, which allows to significantly reduce the level of errors in relation to existing measurement methods and known analogs.The method of digital compensation provides a more significant reduction in the errors of measuring transducers compared with the method of analog compensation. Features and technical indicators of this method are considered on an example of measuring pressure transducer with foil strain gauges.This method is universal, allows us to adjust not only the errors of the measurement channel nonlinearity and additional errors but also the errors associated with the effect of interferences of the general type due to ground resistance, which induces the connection between the measuring channels of the main and destabilizing factor.The disadvantages of this method include a significant amount of computations, which sharply increases with increasing order of approximating polynomials.The purpose is to develop a method and means of measuring stress-strain state using strain gauge, free from the above - mentioned shortcomings.The main destabilizing factors that limit the measurement accuracy using strain gauge are:- random processes (noises, obstacles, etc.);- changes in parameters of measuring transducers due to aging and physical degradation;- effects of external climatic and mechanical factors (temperature, humidity, etc.).The influence of the main destabilizing factors limiting the accuracy of the measurement of the stress-strain state of complex technical constructions with the help of strain gauges was analyzed, among which the influences of external climatic and mechanical factors are one of the most important ones. Regarding the systematic components, the most important in statistical measurements are the errors of nonlinearity and the temperature component of the error.For the study, two main alloys were taken, which today has the widest use as a material for strain gauges - it is constantan and karma. For these materials, the influence of the range of temperature changes, the spread of the values of temperature error on the mean-square value of the error of approximation by power polynomials was investigated.Using the NUMERY package, the dependence of the approximation error on the order of the approximating polyphony was determined. It is established that the mean square error value in the wide temperature range for both constantan and karma has a weak correlation with the order of a polynomial.

scholarly journals Comparison analysis of using micrometers and strain gauges for measuring deformations and loads in the method of monitoring the stress-strain state

2021 ◽  
Vol 18 (3) ◽  
pp. 71-75
Author(s):  
M. O. Lobovskiy ◽  
◽  
A. L. Tukkiya ◽  
P. A. Pyatkin ◽  
◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Strain Gauge ◽  
Laboratory Tests ◽  
Strain State ◽  
Field Tests ◽  
Strain Gauges ◽  
Construction Site ◽  
Comparison Analysis ◽  
Stress Strain ◽  
Stress Strain State

The micrometer method for measuring deformations and loads in bar elements has proved to be effective not only in laboratory tests, but also in field tests on a real construction site. Having carried out a comparative analysis of the method proposed by the authors for monitoring the stress-strain state (SSS) with the strain gauge method which is widely used at present, the authors have proved that the method for measuring deformations and loads using a micrometer is not inferior in accuracy to the strain gauge method, although it is much cheaper.

Investigation of the stress-strain state of beams with different types of web perforation

2021 ◽  
Vol 103 (3) ◽  
pp. 79-87
Author(s):  
Ivan Pidgurskyi ◽  
Vasyl Slobodian ◽  
Denys Bykiv ◽  
Mykola Pidgurskyi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Analytical Calculation ◽  
Complex Stress ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Advantages And Disadvantages ◽  
Stress Strain State ◽  
Element Method

This article is devoted to evaluating the effectiveness of I-beams with different web perforations: hexagonal, round, oval and elliptical. The technology of manufacturing of castellated beams is described. For the purpose of verification the analytical calculation of the beam with hexagonal web perforation and for comparison the calculation by the finite element method is given. To correctly assess the stress-strain state, the mesh of finite elements in the area of openings was concentrated. The results of maximum normal stresses and strains obtained by different methods were compared with each other and the efficiency of using the finite element method to determine the stress-strain state of castellated beams was proved. In the castellated beams there is a complex stress-strain state, which was confirmed in this work for the most characteristic shapes of openings. Beams with hexagonal, round, oval (horizontal and vertical), elliptical and elliptical (rotated by 45°) openings are considered in the article, their geometric parameters and characteristics as well as advantages and disadvantages are described. Beams with round openings are currently the most widely used. In addition, the parameters that affect the efficiency of castellated beams with oval (horizontal and vertical) and elliptical rotated by 45° openings were identified. In this work, it was found that the shape of the openings significantly affects the stress-strain state of the castellated beams, especially for hexagonal openings, which are mainly used so far. The stress distribution in the first opening for each of the considered types of perforations and the nature of the change of σmax in other openings is shown. The stress-strain state of castellated beams was studied using the finite element method. The results of this study are of practical value because they can be used when arranging the sections and openings of castellated beams.

scholarly journals STRESS-DEFORMED STATE OF STEEL-REINFORCED CONCRETE STRUCTURES OF FLOORS AT THE STAGE OF ESTABLISHMENT OF STRUCTURES

2021 ◽  
pp. 101-106
Author(s):  
M. V. Savytskyi ◽  
T.D. NIKIFOROVA ◽  
M. O. FROLOV
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Complex Stress ◽  
Time Interval ◽  
Stress Strain ◽  
Advantages And Disadvantages ◽  
Stress Strain State ◽  
Composite Section ◽  
History Of ◽  
Deformed State

Formulation of the problem. Many structures today require floor structures to meet increased requirements for strength, span coverage and surface quality. Steelcrete structures often fit the bill. However, despite a long history of success, the industry is still not fully understood, in particular, the behavior of this structure in the early stages of construction is not unambiguous. Due to the impossibility of creating a composite section, various effects and a complex stress-strain state immediately arise in the time interval between the combination of different materials in space and the combination of different materials in the work. Thus, the stage of erection of a structure before it became reinforced concrete is of interest for a complete understanding of the mechanics of the work of composite sections. The purpose of the study is to investigate the features of the operation of the steelcrete sections at the stage of installation and operation, as a composite structure that combines the advantages and disadvantages of steel and concrete. As a result of the research, it was found that the study of the stress-strain state, which affects the circumstances, both at the operation stage and at the construction stage, is an important task for further understanding the work of reinforced concrete. , and increasing its durability. In particular, at the time of erection, a complex stress-strain state occurs, which can lead to unpredictable changes in shape. This state is unstable up to the inclusion of the concrete shelf of the reinforced concrete section in the work due to the hardening of concrete in the area of the anchors and its subsequent inclusion in work. These issues require further study in order to better understand the work of concrete and steel as a single composite material at various stages of the life cycle of structures.

scholarly journals Analysis of structural features fixing preventer bonnets

2019 ◽  
pp. 109-113
Author(s):  
Ilez M. Kusiev ◽  
Eduard S. Osipyan
Keyword(s):  
Strain State ◽  
Structural Features ◽  
Strength Calculation ◽  
Stress Strain ◽  
Advantages And Disadvantages ◽  
Stress Strain State

The article analyzes the conditions of the stress-strain state in which preventer bonnets operate. We give the dependences for the strength calculation of fixing preventer bonnets. We identify the advantages and disadvantages of various designs of fastening devices and seals of fasteners. Also, we consider the issues of testing, repairing and operating preventer bonnets.

Investigation of the stress-strain state of lock gates on a strain-gauge model

1988 ◽  
Vol 22 (2) ◽  
pp. 109-113
Author(s):  
V. S. Gavrish ◽  
V. F. Prostak ◽  
V. N. Khimin
Keyword(s):  
Strain Gauge ◽  
Strain State ◽  
Gauge Model ◽  
Stress Strain ◽  
Stress Strain State

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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