scholarly journals Measuring the Temperature and Stress-Strain States of a Tube Sample under the Local Stochastic Temperature Pulsations

2019 ◽  
Vol 10 (1) ◽  
pp. 53-60
Author(s):  
S. M. Dmitriev ◽  
R. R. Ryazapov ◽  
A. V. Mamaev ◽  
A. E. Sobornov ◽  
A. V. Kotin ◽  
...  
Keyword(s):  
Temperature Field ◽  
Nuclear Power ◽  
Strain State ◽  
Technical Problem ◽  
Coolant Flow ◽  
Stress Strain ◽  
Spectral Correlation ◽  
Stress Strain State ◽  
Study Results ◽  
Temperature Pulsations

Provding a high level of durability of heat exchange equipment of water-cooled reactors under local stochastic temperature pulsations is an important scientific and technical problem for the nuclear power industry. Temperature pulsations produced by mixing non-isothermal coolant flows with high temperature gradient are most dangerous. This work is an experimental study of temperature and stress-strain state of a tube sample under local stochastic temperature pulsations caused by mixing of coolant flows.To solve the problems posed, aY-junction with «counter injection» was built, which was included in the thermal-hydraulic research facility. The design of theY-junction allows study of the thermal-hydraulic characteristics and durability of tube samples made of austenitic steel of 60 × 5 мм. Some tube samples had developed for measuring the temperature, stress-strain state of tube material and temperature field of coolant flow in mixing zone of single-phase coolants with different temperatures. Measuring tube samples were equipped with micro thermocouples and strain gauges.The experimental data of temperature pulsations, time-averaged temperature field in the coolant flow and on the outer surface of the sample were obtained, and statistical and spectral correlation characteristics of temperature pulsations were analyzed. According to results of measuring the relative strain, values of stresses were calculated.Devices and research techniques are developed. The combination of coolant flows parameters that provide thermal load of the metal surface at the highest level of stress intensity amplitude was obtained. The study results are used to verify the method for evaluating fatigue of reactor installations materials under stochastic temperature pulsations.

Simulating the stress–strain state of a thin plate after a thermal shock

2021 ◽  
Author(s):  
A. V. Sedelnikov ◽  
S. V. Glushkov ◽  
V. V. Serdakova ◽  
M. A. Evtushenko ◽  
E. S. Khnyryova
Keyword(s):  
Temperature Field ◽  
Thermal Shock ◽  
Thin Plate ◽  
Strain State ◽  
Stress Strain ◽  
Homogeneous Plate ◽  
Stress Strain State ◽  
The Impact ◽  
Elastic Elements

The paper is devoted to simulating the impact of a thermal shock on a thin homogeneous plate in the ANSYS package. The assessment of the stress–strain state is carried out and the dynamics of changes in the temperature field of the plate is determined. The obtained results were compared with the data of other authors and can be used when taking into account the thermal shock of large elastic elements of spacecraft.

scholarly journals ТЕОРЕТИЧНЕ ДОСЛІДЖЕННЯ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ БАЗОВИХ ПЛИТ УЗРП-16

2020 ◽  
pp. 151-164
Author(s):  
Є. А. Фролов ◽  
Б. О. Коробко ◽  
С. В. Попов
Keyword(s):  
Strain State ◽  
Structural Parameters ◽  
Plate Thickness ◽  
Bending Moment ◽  
Base Plate ◽  
Plate Surface ◽  
Stress Strain ◽  
Stress Strain State ◽  
Study Results ◽  
Base Plates

Theoretical studies of the stress-strain state of base plates, which are the base of the UZRP-16 universal collapsible machines have been done. These machines are used for welding works in machine building industry. The finite element method was applied to solve the problems. Nature of influence of strength and structural parameters on the base plate stress-strain state in operation has been determined, namely: the relations between displacements and stresses arising in the base plates and the bending moment magnitudes have been recorded; the stress-strain state pattern of the base plates has been obtained depending on the place of bending moment application; influence of the conditions for bearing and fastening the plates on their stress-strain state has been investigated; influence of the plate geometric parameters on stress and displacement has been studied; The stress-material and displacement-material relations have been obtained for the plates. Based on the theoretical study results of the base plate stress-strain state, the following have been obtained: stress plots and patterns of deformed surfaces, which are symmetrical with respect to the plate central axes; maximum values of normal and tangential stress components arising in the field of bending moment application; stress on the rectangular base plate surface is 2.1 times higher than the stress on square plate surface under the same conditions of bearing and loading; stresses acting on the plate surfaces and being tensile stresses within the range of 10 to 70 MPa. It was found that the square shape of the plates, according to the stress state, is predominant in relation to the rectangular shape. The optimal condition for bearing is fixing the plates at nine points. For the first time, graphs were drawn for choosing the base plate thickness under action of various operational loads.

Application of the Expert System for Assessing of the Stress-Strain State of Nuclear Power Plant Containments at the Stage of Construction and Operation

2019 ◽  
Vol 14 (1) ◽  
pp. 25-38
Author(s):  
V.N. Medvedev ◽  
Aleksandr S. Kiselev ◽  
Aleksei S. Kiselev ◽  
V.F. Strizhov ◽  
A.N. Ul'yanov ◽  
...  
Keyword(s):  
Expert System ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State

Effect of the layout of small-and large-series WWER-1000 reactors of nuclear power plants on the stress-strain state of the header-steam generator connector weldment

2007 ◽  
Vol 39 (5) ◽  
pp. 539-544 ◽  
Author(s):  
G. V. Stepanov ◽  
V. V. Kharchenko ◽  
A. I. Babutskii ◽  
S. V. Kobel’skii ◽  
I. V. Orynyak ◽  
...  
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Strain State ◽  
Large Series ◽  
Stress Strain ◽  
Stress Strain State

scholarly journals Specific features of thermal deforming of composite inductors during magnetic-pulse processing of materials

2021 ◽  
pp. 127-130
Author(s):  
Galina Ottovna Anishchenko ◽  
Vladimir Ivanovich Konokhov ◽  
Denis Vladimirovich Lavinsky
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Strain State ◽  
Nonlinear Effects ◽  
Magnetic Pulse ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Pulse Processing ◽  
Stress Strain State ◽  
Field Temperature

The problem of taking into account a non-stationary inhomogeneous temperature field in the analysis of the stress-strain state of inductor systems for magnetic-pulse processing of materials is considered. It follows from the analysis of open information sources that the problem of analyzing a non-stationary temperature field arising from the presence of a non-uniform electromagnetic field and its effect on deformation has been sufficiently studied in relation to induction heating. At the same time, during other operations of magnetic-pulse processing of materials, heating of equipment can cause additional deformations of a significant magnitude, which, in turn, can lead to a loss of equipment performance due to destruction or irreversible deformation. A general approach to the analysis of such problems is proposed, which involves the determination of the spatial-temporal distributions of the quantitative characteristics of the electromagnetic field, temperature field and stress-strain state. The necessity of using numerical methods for carrying out such an analysis has been substantiated. The most effective numerical method is the finite element method, which makes it possible to analyze the unsteady electromagnetic field, temperature field, and stress-strain state within the same calculation scheme. In this case, within the framework of the finite element method, iterative schemes can be created that allow taking into account nonlinear effects. Here, nonlinear effects can be due to the dependence of the mechanical and electro-physical properties of the material on temperature, the plastic nature of deformation, and the need to take into account contact phenomena. The results of complex analysis for a composite single-turn inductor with a dielectric band are presented. The features of contact interaction were taken into account by introducing layers of contact finite elements. The stress-strain state of the inductor is estimated for two variants of the materials used: copper and non-magnetic steel.    

scholarly journals STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION

2020 ◽  
Vol 5 (4) ◽  
pp. 51-59
Author(s):  
Alexander Schmidt ◽  
Keyword(s):  
Strain State ◽  
Initial Stresses ◽  
Internal Stresses ◽  
Shear Stresses ◽  
Stress Strain ◽  
Stress Strain State ◽  
Operational Load ◽  
Study Results ◽  
The Impact ◽  
Wooden Structures

Introduction: The stress-strain state (SSS) of curved laminated wooden elements may differ significantly from the SSS of straight laminated wooden elements, not only in terms of the curvature but also in terms of production specifics and operational load. A curved element is produced by bending wooden planks (lamellae) and gluing them together. In the process, the structure is subjected to initial internal stresses, as the lamellae tend to straighten out again. After production is complete, the element experiences unequal initial internal stresses, which alters its strength properties in different directions in relation to the timber fibers. At a later point, this is going to contribute to the stresses that the structure experiences under external pressure. The Russian and foreign regulations (SP, EuroCode 5, DIN) do not pay sufficient attention to this fact, which has merited this study. Methods: For the aforementioned purpose, we review a mathematical model of the SSS emergence in curved laminated wooden elements. We roughly divide the process into two stages: stage 1 involves bending separate lamellae, gluing them together, and pressing them down; stage 2 involves pressing out the laminated package. This results in prestress, which is a combination of tangential, radial, and shear stresses. Results: Our study results in a visual representation of the total prestress during stages 1 and 2. Such a representation allows for predicting stresses in curved laminated wooden structures under alternating operational loads. Discussion: We highlight the impact of the relaxation of initial stresses, which requires further study. Depending on the direction and amount of operational load, the curved laminated section of a structure may “attempt” to straighten out (i.e. with a decrease in curvature), or may curve even further. This is not properly reflected in the guidelines for wooden structures’ design and needs to be examined further.

scholarly journals Experimental studies of temperature pulsations during the process of mixing non-isothermal coolant flows in nuclear reactor equipment components

2019 ◽  
Vol 5 (3) ◽  
pp. 225-229
Author(s):  
Sergey M. Dmitriev ◽  
Alexandr V. Mamaev ◽  
Renat R. Ryazapov ◽  
Aleksey Ye. Sobornov ◽  
Andrey V. Kotin ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Single Phase ◽  
Experimental Studies ◽  
Coolant Flow ◽  
Mixing Zone ◽  
Stress Strain ◽  
Austenite Steel ◽  
Experimental Section ◽  
Temperature Pulsations

One of the most important scientific and technical tasks of the nuclear power industry is to assure the reactor equipment life and reliability under random temperature pulsations. High-intensity temperature pulsations appear during the process of mixing non-isothermal coolant flows. Coolant thermal pulsations cause corresponding, sometimes very significant, fluctuations in the temperature stresses of the heat-exchange surface metal, which, added to static loads, can lead to fatigue failure of equipment components. The purpose of this work was to conduct an experimental study of the temperature and stress-strain states of a pipe sample under the influence of local stochastic thermal pulsations caused by the mixed single-phase heat coolant flows. To solve the set problems, an experimental section was created, which made it possible to simulate the process of mixing non-isothermal coolant flows accompanied by significant temperature pulsations. The design of the experimental section allowed us to study the thermohydraulic and life characteristics of pipe samples made of austenite steel (60×5 mm). Some tools were developed for measuring the pipe sample stress-strain state and the coolant flow temperature field in the zone of mixed single-phase media with different temperatures. The measuring tools were equipped with microthermocouples and strain sensors. As a result, we obtained experimental data on temperature pulsations, time-averaged temperature profiles of the coolant flow in the mixing zone as well as statistical and spectral-correlation characteristics of thermal pulsations. Based on the results of measuring the relative strains, the values of fatigue stresses in the mixing zone were calculated. In addition, some devices and methods were elaborated to measure the temperature and stress-strain states of the pipe sample under the influence of local stochastic thermal pulsations. The developed experimental section provided thermal-stress loading of the metal surface at a high level of alternating stress amplitudes causing rapid damage accumulation rates. The results were included in the database to verify the method for assessing the fatigue life of structural materials for nuclear power plants as applied to austenite steel 12Cr18Ni10Ti under the influence of random thermal cyclic loads.

Sign in / Sign up

Export Citation Format

Share Document