Electromagnetic Methods for Testing Changes in Stress-Strain State of Dielectric Materials

2021 ◽  
Vol 57 (10) ◽  
pp. 865-876
Author(s):  
A. A. Bespal’ko ◽  
D. D. Dann ◽  
M. V. Petrov ◽  
E. K. Pomishin ◽  
G. E. Utsin ◽  
...  
Keyword(s):  
Strain State ◽  
Dielectric Materials ◽  
Stress Strain ◽  
Stress Strain State ◽  
Electromagnetic Methods

Criterion for Controlling the Stress-Strain State of Composite Dielectric Materials Using the Effective Filtration Method

2018 ◽  
Vol 781 ◽  
pp. 108-113
Author(s):  
Vladimir Surzhikov ◽  
Pavel Fedotov
Keyword(s):  
Strain State ◽  
Dielectric Materials ◽  
Mirror Image ◽  
Electromagnetic Response ◽  
Stress Strain ◽  
Coherent Signal ◽  
Filtration Method ◽  
Stress Strain State ◽  
Left And Right ◽  
Sand Filler

The paper presents a brief description of a process of an electromagnetic response generation from dielectric composite materials when they are subjected to an acoustic impulses, a recording method by capacitive receivers and criteria for controlling the stress-strain state (SSS) for this method. Also there are the results of studies of the applicability of the effective filtration method for the control of similar products from epoxy resin with sand filler. The formation of a response with a pronounced maximum and an excitation pulse symmetric with respect to the end time is determined when a coherent signal is input to the input of the system, which is a mirror image of the impulse response. The correlation coefficient between the left and right parts of the response was chosen as a criterion for controlling the SSS.

Analyzing Deformation and Fracture of Dielectrics by Integral Characteristics of their Electromagnetic Emission

2016 ◽  
Vol 683 ◽  
pp. 36-43 ◽  
Author(s):  
Ludmila Yavorovich ◽  
Anatoly Bespal’ko ◽  
Pavel Fedotov ◽  
Aleksey Popelyaev
Keyword(s):  
Strain State ◽  
Electromagnetic Emission ◽  
High Strength ◽  
Dielectric Materials ◽  
Stress Strain ◽  
Rock Samples ◽  
Stress Strain State ◽  
Local Strength ◽  
Deformation And Fracture ◽  
Integral Characteristics

Revealing of fracture harbingers of dielectric materials, that are under mechanical stress, is an important practical and scientific problem. Local stresses, produced by mechanical impact, can exceed the local strength, and a stress-strain state changes. As the result of such impacts, microcracks appear and lead to fracture. During change of stress-strain state, mechanoelectric transformations occur, that generate electromagnetic emission. So we aimed to observe regularities in electromagnetic emission characteristics. Rock samples, collected from Tashtagol ore-mine of Kemerovo region of Russia, were used as dielectric materials for the research. For analysis of rock samples deformation and fracture, integral characteristics of time series of electromagnetic emission were used. Observed, that low-strength samples accumulate and relax elastic energy stepwise unlike to high-strength samples, that accumulate energy linearizely. Differences in dispersion characteristics of samples differing with strength are observed. The research showed usability of suggested algorithms.

On a criterion for testing the stress-strain state of dielectric materials

2017 ◽  
Vol 53 (3) ◽  
pp. 213-219
Author(s):  
V. P. Surzhikov ◽  
N. N. Khorsov ◽  
A. A. Demikhova
Keyword(s):  
Strain State ◽  
Dielectric Materials ◽  
Stress Strain ◽  
Stress Strain State

The Application of Reverberation in Method of Mechanoelectrical Transformations for Estimation of Stress-Strain State in Solid Dielectrical Matter

2019 ◽  
Vol 970 ◽  
pp. 47-54
Author(s):  
Petr Khorsov ◽  
Roman Laas ◽  
Anatoly P. Surzhikov
Keyword(s):  
Statistical Analysis ◽  
Acoustic Waves ◽  
Strain State ◽  
Mechanical Load ◽  
Dielectric Materials ◽  
Random Component ◽  
Differential Analysis ◽  
Stress Strain ◽  
Stress Strain State ◽  
Mechanoelectrical Transformations

The paper assesses the possibility of using the reverberation phenomenon to control the imperfections and the stress-strain state of solid dielectric materials by the method of mechanoelectrical transformations. The main advantage of reverberation is the repeated intersections of the excitation zones of inhomogeneities by acoustic waves, that is displayed in response parameters. The reverberation makes it possible to accumulate distortions of wave fronts. A comparative analysis of the responses from the sample under condition of uniaxial compression under different loads was performed. Differential analysis for the deterministic time component of the response in the interval (0–0.3) ms, and a statistical analysis of the differences for the pseudo-random component in the interval (0.8–1.8) ms were performed. For the statistical analysis, the distribution of the pulse flow is selected. The response was calculated according to the mathematical model under the conditions of a change in the speed of sound, which simulates a change in the sample inhomogeneity under load. The calculation showed a qualitative similarity with changes in responses in a real experiment. According to the obtained results, it was concluded that it is possible to use the deterministic and pseudo-random components of the responses in the reverberation condition to control the change in defectiveness and the degree of heterogeneity under the action of the mechanical load on the sample.

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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