scholarly journals ABOUT THE STRESS STATE ON THE CONTOURS OF UNDERGROUND HORIZONTAL WORKINGS, SUBJECT TO AN OVERALL UNIFORM PRESSURE

2019 ◽  
Vol 7 (1) ◽  
pp. 49-60
Author(s):  
Оксана Богомолова ◽  
Oksana Bogomolova ◽  
Андрей Ушаков ◽  
Andrej Ushakov
Keyword(s):  
Stress State ◽  
Cross Section ◽  
Expansion Coefficient ◽  
Uniform Pressure ◽  
Lateral Expansion ◽  
Underground Workings ◽  
The Cross ◽  
Graphic Images ◽  
The Given ◽  
Distribution Of Stresses

The paper presents the results of a study on the distribution of stresses on the contours of underground workings, the cross section of which has the form of a trapezoid and an ellipse. The distribution of stresses at the points of workings contours is obtained at the given values of uniform pressure and the lateral expansion coefficient of the rock. The graphic images of stress diagrams acting on the contours of the considered workings are given.

scholarly journals INFLUENCE OF THE SHAPE AND DIMENSIONS OF THE CROSS SECTION OF UNDERGROUND WORKINGS ON THE MAGNITUDE OF THE RAINFALL SURFACE

2017 ◽  
Vol 8 (2) ◽  
pp. 123-134
Author(s):  
Aleksandr Bogomolov ◽  
◽  
Oksana Bogomolova ◽  
Ekaterina Stepanova ◽  
Andrei Ushakov
Keyword(s):  
Cross Section ◽  
Underground Workings ◽  
The Cross

scholarly journals ПОЛНЫЕ ДИАГРАММЫ РАЗВИТИЯ ДЕСТРУКЦИЙ ОДНОРОДНО И НЕОДНОРОДНО СЖАТОГО БЕТОНА ПРИ ОСЕВОМ И ВНЕЦЕНТРЕННОМ НАГРУЖЕНИИ БЕТОННЫХ КОРОТКИХ КОЛОНН

2019 ◽  
Author(s):  
V. Sovgira ◽  
V. Sovgira
Keyword(s):  
Stress State ◽  
Cross Section ◽  
Concrete Columns ◽  
Load Level ◽  
Transverse Deformation ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Loading Mode ◽  
The Cross ◽  
Increasing Load

В статье приведены результаты выполненных исследований механизма интенсивности развития деструкций, псевдопластического деформирования и разрушения однородно и неоднородно сжатого тяжелого бетона призменной прочностью в диапазоне fc1522,265,6 МПа при мягком и жестком режиме нагружения одноосно и внецентренно сжатых бетонных колонн. Выполнен анализ литературных источников с исследованиями изменения упруго-пластических характеристик vc, Еcsek тяжелого бетона с учетом влияния значимых факторов и их изменение с увеличением уровня нагрузки при описании зависимости c-cх и c,е - cх,е. Установлено, что рекомендованные Строительными Нормами vcи и Ес одноосно сжатого бетона количественно и качественно не отражают характер изменения упруго-пластических свойств неоднородно сжатого бетона с ростом уровня нагрузки. Предложены аналитические выражения зависимости изменения коэффициентов упругости (vc, vc,е), секущих модулей упругости (Еcsek, Еc,еsek) и коэффициентов интенсивности развития деструкций (KD, KD,е) однородно и неоднородно сжатого бетона с ростом уровня нагрузки при мягком и жестком режиме нагружения исследованных серий тяжелого бетона с использованием сlx сlx,е Ес Nc,e/Ncu,e сu и сu,е, отражающих процесс изменения упруго-пластических свойств бетона на восходящих и нисходящих участках полных диаграмм деформирования бетона и их существенное отличие при центральном и внецентренном сжатии. Исследованиями отмечено, что интенсивность развития деструкций в структуре неоднородно нагруженного бетона существенно ниже, чем в одноосно сжатом. Экспериментами установлено характерное изменение по высоте сечения внецентренно сжатых бетонных элементов коэффициента поперечных деформаций , свидетельствующее о том, что с увеличением уровня нагрузки коэффициент наиболее сжатой фибры на всех уровнях нагрузки, значительно (в 1,21,5 раза) меньше волокон менее нагруженных фибр. Отмеченное свойство обусловлено изменением внутреннего напряженного состояния с ростом нагрузки и перераспределением напряжений силовыми связями структуры неоднородно сжатого бетона с субмикро- и микроуровней волокон наиболее нагруженной грани по высоте сечения внецентренно сжатых элементов на менее нагруженные волокна. Этот процесс перераспределения напряжений по высоте сечения бетонных колонн как свойство проявляется на изменении поперечной деформации cу,е и, как следствие изменения коэффициента поперечной деформации , влияющего на напряженное состояние сжатой зоны подобно внутренним силовым связям, обеспечивающим существенное повышение максимальных напряжений и деформаций в неоднородно сжатом бетоне.The article presents the results of studies of the intensity of development of destructions, pseudoplastic deformation and destruction of uniformly and non-uniformly compressed heavy concrete with prism strength in the range of fc1522,265,6 MPa in the soft and hard loading mode of uniaxially and eccentrically compressed concrete columns. The analysis of literary sources with studies of changes in the elastic-plastic characteristics of vc, Еcsek heavy concrete, taking into account the influence of significant factors and their change with increasing load level when describing the dependence c-cх and c,е - cх,е . It has been established that the vcu and Ес recommended by the Building Norms of uniaxially compressed concrete do not quantitatively and qualitatively reflect the nature of the change in the elastic-plastic properties of non-uniformly compressed concrete with increasing load levels. Analytical expressions are proposed for the dependence of the change in elasticity coefficients (vc, vc,е), cross-section elastic modulus (Еcsek, Еc,еsek) and the intensity factors for the development of destructions (KD, KD,е) of uniformly and non-uniformly compressed concrete and hard loading mode of the studied series of heavy concrete using: сlx сlx,е Ес Nc,e/Ncu,e сu and сu,е , reflecting the process of changing the elastic-plastic properties of concrete in the ascending and descending parts of the complete concrete deformation diagrams and their significant difference under uniaxial and eccentrically compression. Studies have noted that the intensity of the development of destructions in the structure of non-uniformly loaded concrete is significantly lower than in uniaxially compressed. Experiments established a characteristic change in the height of the cross section of eccentrically compressed concrete elements of the transverse strain coefficient , indicating that with an increase in the load level, the coefficient of the most compressed fiber at all load levels is significant (1,2-1,5 times) less fibers, less loaded fibers. This property is caused by the change in the internal stress state with increasing load and stress redistribution by force bonds of the structure in non-uniformly compressed concrete from submicro- and microlevels of the fibers of the most loaded face along the height of the cross section of eccentrically compressed elements to less loaded fibers. This process of stress redistribution along the height of the cross section of concrete columns as a property manifests itself in a change in transverse deformation cу,е and, as a result, a change in the transverse deformation coefficient , affecting the stress state of the compressed zone, similar to internal force connections, providing a significant increase in maximum stresses and strains in non-uniformly compressed concrete.

MEASUREMENT OF THE HADRONIC CROSS SECTION VIA RADIATIVE RETURN AT DAΦNE

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1935-1938 ◽  
Author(s):  
◽  
ACHIM G. DENIG
Keyword(s):  
Cross Section ◽  
Mass Range ◽  
Initial State ◽  
Hadronic Contribution ◽  
Electron Positron ◽  
State Radiation ◽  
Radiative Return ◽  
Radiator Function ◽  
The Cross ◽  
The Given

The cross section σ(e+e-→π+π-γ) has been measured with the KLOE detector at the electron-positron collider DAΦNE, at an energy W=mϕ=1.02 GeV . We perform this measurement as a function of the π+π- invariant mass, Mππ. The photon in the above process is due to Initial State Radiation. Dividing by a theoretical radiator function, we obtain the cross section σ(e+e-→π+π-) for the mass range [Formula: see text] with an overall accuracy of 1.3%. We also calculate the hadronic contribution of the two-pion channel to the anomalous magnetic moment of the muon for the given mass range: [Formula: see text].

scholarly journals ON THE DETERMINATION OF STRESSES ON THE CONTOURS OF UNDERGROUND HORIZONTAL MINES, SUBJECT TO AN OVERALL UNIFORM PRESSURE

2019 ◽  
Vol 10 (2) ◽  
pp. 36-55
Author(s):  
A. N Bogomolov ◽  
O. A Bogomolova ◽  
A. N Ushakov
Keyword(s):  
Stress State ◽  
Mapping Function ◽  
Uniform Pressure ◽  
Cross Sectional ◽  
Elliptical Cross ◽  
Variable Function ◽  
Graphic Representations ◽  
Underground Mine Workings ◽  
Underground Workings

The paper presents the results of a study to determine the stress state on the contours of underground workings, the cross section of which has the form of a trapezium, a triangle, a rectangle, a rhombus, astroids and an ellipse. The strength of underground workings of trapezoidal and elliptical cross-sectional shapes was studied for given values of uniform pressure applied at the points of the outlines of the workings. The analysis of the stress state at the points of the contours of underground mine workings has been carried out. As a mapping function, a complex variable function is used, which is a third degree polynomial. The stress state at the boundary of the underground horizontal excavation, which has a predetermined shape, is investigated depending on the value of the numerical pressure value acting along this boundary with a predetermined value of the lateral distribution coefficient. Graphic representations of stress diagrams acting on the contours of the workings are given.

scholarly journals Influence of the Cross-Sectional Shape of a Reinforced Bimodular Beam on the Stress-Strain State in a Transverse Impact

Buildings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 248
Author(s):  
Alexey Beskopylny ◽  
Elena Kadomtseva ◽  
Besarion Meskhi ◽  
Grigory Strelnikov ◽  
Oleg Polushkin
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Cross Section ◽  
Strain State ◽  
Transverse Impact ◽  
Stress Strain ◽  
Cross Sectional ◽  
Stress Strain State ◽  
The Cross ◽  
The Impact

The paper considers the stress-strain state of a reinforced concrete beam, as a bimodular material, under the action of an impact. The behavior of bimodular concretes with different moduli of elasticity in tension and compression has not been studied enough. At the same time, taking into account the bimodularity of concrete makes it possible to design a more economical structure, especially for dynamic load. In this article, the impact is considered as an absolutely plastic impact of an absolutely rigid body on an elastic system. The stress state is investigated for beams of rectangular, T-section and I-sections, and is compared with and without the bimodularity of reinforced concrete. The analysis of the dependence of the stress state on the shape, cross-sectional dimensions, and the location of reinforcing bars in the compressed and tensioned zones was carried out for lightweight concrete (Et < Ec) and for heavy concrete (Et > Ec) under the action of shock load with and without regard to the mass of the beam. The numerical study shows that taking into account the mass of the beam upon impact significantly decreases the magnitude of the normal stresses in both the tensioned and compressed zones. Beams of rectangular cross-section have the highest load-bearing capacity when the cross-section height is equal for both light and heavy concrete. An increase in the size of the flange of the I-beam in the stretched zone leads to a sharp decrease in normal tensile stresses and a slight increase in normal compressive stresses. The proposed engineering method makes it possible to numerically study the effect on the stress-strain state of a beam under the action of a concentrated impact of various geometric characteristics of the cross-section, bimodularity of the material, size, number and location of reinforcement.

Calculation of Bending Stiffness and its First Derivatives Related to Optimization of a Steel-Reinforced Concrete Cross Section

2016 ◽  
Vol 249 ◽  
pp. 253-260 ◽  
Author(s):  
Jakub Venclovský ◽  
Petr Stepanek
Keyword(s):  
Cross Section ◽  
Bending Stiffness ◽  
Steel Reinforced Concrete ◽  
Reduced Gradient Method ◽  
Final Output ◽  
Reduced Gradient ◽  
The Cross ◽  
Input Variables ◽  
The Given ◽  
Derivatives Of

This article focuses on creating an algorithm for the calculation of bending stiffness of an arbitrary polygonal cross section, including the first derivatives of this stiffness with respect to all the input variables. The coordinates of vertices of the cross section are also among these input variables. The algorithm is in principle based on dividing the cross section into trapezoids, calculating zero, first and second moment of area of these trapezoids, including partial derivatives with respect to all the input variables, and then compiling all these partial results into a final output. A DLL library based on this algorithm is then used in an optimization solver based on a reduced‑gradient method. This solver is put into practice to optimize the given cross section characteristics according to prescribed criteria.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

Research in the cross-section of community psychology and global climate change: A call for action

2009 ◽  
Author(s):  
Marci Culley ◽  
Holly Angelique ◽  
Courte Voorhees ◽  
Brian John Bishop ◽  
Peta Louise Dzidic ◽  
...  
Keyword(s):  
Climate Change ◽  
Cross Section ◽  
Global Climate Change ◽  
Community Psychology ◽  
Global Climate ◽  
The Cross
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