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

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.

2018 ◽  
Vol 781 ◽  
pp. 108-113
Author(s):  
Vladimir Surzhikov ◽  
Pavel Fedotov

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.


2019 ◽  
Vol 27 (4) ◽  
pp. 488-503
Author(s):  
Alexandr Anatolyevich Treschev ◽  
Alexander Anatolyevich Bobryshev ◽  
Victor Grigoryevich Telichko ◽  
Lenar Nurgaleevich Shafigullin ◽  
Alexander Valeryevich Bashkatov

In this article, the construction of finite-elemental model of definition of stress-strain state of reinforced concrete plates in conditions of active deformation and simple loading in combination with long-term influence of chloride-containing operating environment. Non-linear behavior of concrete is simulated based on the determining relations proposed by Treschev, cracking and plastic deformations in armature are taken into account. The impact of the aggressive environment is taken into account in accordance with the model proposed by Petrov and Penina. In the article all basic correlations of finite elements method in convenient for software realization on a computer are given. As the object of research for this article is a concrete plate reinforced with steel reinforcement in a stretched area, which is under the joint influence of mechanical load and aggressive chloride-containing environment on the protective polymer–concrete layer. The load was taken evenly distributed across the entire slab area. At the solution of this problem the non-linear sensitivity of the basic material (concrete) to the type of the tense condition, plastic deformations in armature, degradation of a protective concrete at influence of external aggressive environment are taken into account. In the article some especially characteristic results of mathematical modeling of the specified model problem are given. The obtained results of joint influence on the plate of mechanical load and aggressive environment are analyzed.


2020 ◽  
Vol 1 (2) ◽  
pp. 159-171
Author(s):  
Yuliya Andreevna LAGUNOVA ◽  
◽  
Stanislav Anatol’evich MAYOROV ◽  
Gennadiy Alexeevich BOYARSKIH ◽  
◽  
...  

The relevance of the work. When creating particularly large machines and systems, in the case of their 3D modeling and detailed study, the load on the central processor of the computer, as well as on the graphic and RAM modules, increases, which significantly slows down the design process and calculations. In the article, a statistical analysis of the stress-strain state of the jaw crusher bearing is carried out to establish the correspondence of the theoretical and actual structural models taking into account all workloads. The objectives of the study. Consider the task of selecting a simpler and “easier” for the calculation model programs, not difficult to parameterize, compared with the original bearing model, but providing accuracy in the calculation in an acceptable range of errors. To analyze the stress-strain state of the bearing assembly with various geometric parameters. Research methodology. In the calculations, the finite element method was used. Used specialized software package APM WinMachine. A computational experiment was conducted. A correlation analysis of the theoretical and actual structural model of the bearing is carried out. Results. Mathematical models of the metal structures of bearings of various sections are given and the locations of the highest stresses are identified. Calculation errors and correlation dependencies of stresses are established taking into account the Pearson, Fisher criteria and the construction of the Taylor series. Conclusions. The results of a computational experiment satisfy the requirements and can be used to solve further problems of designing bearing assemblies. In the future, a parameter-dependent model can be created that makes it easier to calculate using any type of bearing


2016 ◽  
Vol 683 ◽  
pp. 36-43 ◽  
Author(s):  
Ludmila Yavorovich ◽  
Anatoly Bespal’ko ◽  
Pavel Fedotov ◽  
Aleksey Popelyaev

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.


2017 ◽  
Vol 53 (3) ◽  
pp. 213-219
Author(s):  
V. P. Surzhikov ◽  
N. N. Khorsov ◽  
A. A. Demikhova

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 ◽  
...  

Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик

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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