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.

scholarly journals Determination of loading modes for endurance tests of reinforced concrete sleepers on the basis of experimental measurement of their stress state under the conditions of the Test Loop at Shcherbinka

2021 ◽  
Vol 80 (3) ◽  
pp. 127-135
Author(s):  
O. A. Suslov ◽  
N. V. Ressina ◽  
A. V. Portnov ◽  
A. A. Novikov ◽  
V. A. Mariychuk
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Strain State ◽  
Stress Strain ◽  
Bench Tests ◽  
Stress Strain State ◽  
Test Loop ◽  
Endurance Tests ◽  
Loading Modes ◽  
The Impact

The article considers the issue of changing the stressstrain state of reinforced concrete sleepers depending on the value of the axle loads and the requirements for the modes of its bench endurance tests. This issue is very relevant, since at present, in certain sections of the network (directions of the Eastern operational area), due to the high traffic density, the impact on the track increases and the axle load increases. Such a change entails the need to revise the requirements for the methods for determining and confirming the resource of all track elements, including the loading modes of reinforced concrete sleepers during its bench tests. To determine the influence of the axle load, measurements were made of the actual stress-strain state of reinforced concrete sleepers laid on the tangent section of the Test Loop of the JSC “VNIIZHT”. The loading was realized by a running train of 72 cars and a specially formed experimental coupler of a locomotive and three cars with an axle load of 23.5, 25 and 27 tf, respectively. Measurements made it possible to obtain the dependence of the change in stresses and deformations on the change in the axle load, as well as to reveal the rheological features of the interaction of reinforced concrete sleepers and the ballast layer. Obtained measurement results were used as basic stresses and strains for calculating loading modes in bench endurance tests. Purpose of the calculation is to achieve the maximum identity of the stress state when the sleepers are loaded on the bench with its stress state during real operation. In addition, experimental bench loading of a reinforced concrete sleeper was carried out, during which the modes obtained by the calculation were implemented and its stress-strain state was measured. Results of comparing the stress state of a reinforced concrete sleeper obtained during full-scale measurements on the way and during loading on the stand showed their identity, which confirmed the adequacy of the calculated loading modes. The final result of the work was the loading modes for bench tests of reinforced concrete sleepers, taking into account the influence of the axle load value.

scholarly journals The Stress-Strain State of the Drill String at the Section of the Borehole with a Cavern

2016 ◽  
Vol 5 (2) ◽  
pp. 122
Author(s):  
Ruslan Rachkevych ◽  
Iryna Rachkevych
Keyword(s):  
Cross Section ◽  
Relative Position ◽  
Strain State ◽  
Drill String ◽  
Transverse Load ◽  
Bending Stress ◽  
Stress Strain ◽  
Stress Strain State ◽  
Drill Pipes ◽  
The Cross

<p class="1Body">This study analyses the stress-strain state of a drill string at the section of the borehole with a cavern/chute. The study was conducted to obtain analytical dependencies to determine normal bending stress in the cross section of the drill string and its downforces to the walls of the well. This will allow to compare these values with the critical ones, and draw conclusions about the possibility and duration of the drill string operation under these conditions.</p><p class="1Body">The study is based on modelling the drill string as a beam, which indicates longitudinal and transverse load and deforms in-plane.</p><p class="1Body">The formulas obtained to determine stresses and pressing forces apply to the following cases of the relative position of the drill string in a straight borehole and a curved borehole with a cavern/chute: a – the drill string touches only the bottom of the borehole; b – the drill string touches only the bottom of the borehole and the bottom of the cavern/chute; c –  the drill string touches the top and the bottom of the borehole; d – the drill string touches the top and the bottom of the borehole and the cavern/chute.</p><p class="1Body">The calculations based on the dependencies obtained lead to the following conclusions: a – the cavern/chute in the inclined straight borehole causes bending stress value in the cross section of drill pipes proportional to the fatigue margin of the material; b – the cavern/chute in the curved borehole may increase normal bending stress in the cross section of the borehole up to five times.</p>

scholarly journals Static analysis of a reinforced bimodulus beam on elastic foundation

2018 ◽  
Vol 196 ◽  
pp. 02003 ◽  
Author(s):  
Alexey Beskopylny ◽  
Elena Kadomtseva ◽  
Grigory Strelnikov
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Strain State ◽  
Building Materials ◽  
Elastic Base ◽  
Reinforced Concrete Beams ◽  
Building Structures ◽  
Maximum Deflection ◽  
Stress Strain ◽  
Stress Strain State

The work considers a reinforced concrete beam made of bimodule material on an elastic Winkler base. The influence of the number of reinforcing bars located in the stretched zone on the maximum normal stress and the maximum deflection is numerically investigated. The choice of the cross-section dimensions, such as the width and thickness of the flanges, the height of the beam, causes particular difficulties and is limited by the need to determine specific ratios of I-beam sizes. Numerical investigation allows analyzing the influence of the width of the I-beam flange that is in contact with the elastic base on the maximum tensile stresses and maximum deflection. The effect on the stressed-deformed state of the various cross-section forms is carried out in work for an I-beam, a rectangle, and a T-beam. Related to the fact that for many building materials the elastic moduli for tension and compression differ, it became necessary to determine the influence of material heterogeneity on the stress-strain state of the elements of building structures. In particular, the widespread use of reinforced concrete beams as elements of band foundations requires a refinement of the stress-strain state study taking into account the heterogeneity of concrete.

scholarly journals Investigation of the bearing capacity of reinforced concrete beams strengthened with reinforced concrete ring under load

2014 ◽  
Vol 13 (3) ◽  
pp. 065-070
Author(s):  
Zinoviy Blikharskyy ◽  
Dmytro Dubizhanskyy ◽  
Roman Khmil
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Strain State ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Stress Strain ◽  
Normal Cross Section ◽  
Stress Strain State ◽  
Concrete Ring

Bearing capacity of normal cross section of bending concrete elements reinforced with reinforced concrete ring under load was investigated. Experimental researches of 4 sets of beams with the total number of 16 units were carried out. The results of changes of stress-strain state settings depending on the load level, additional reinforcement, influence of limit level load were analyzed. The three characteristic stages of stress-strain state of reinforced concrete beams strengthened with reinforced concrete ring were defined. Results of experimental investigations of bearing capacity of normal cross section of strengthened beams with reinforced concrete ring under load were presented. Enhancing effect was calculated. According to the results of researches of strengthened beams plots of strain of working armature depending on current bending moment were constructed.

scholarly journals Transverse Impact on Rectangular Metal and Reinforced Concrete Beams Taking into Account Bimodularity of the Material

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1579 ◽  
Author(s):  
Alexey Beskopylny ◽  
Besarion Meskhi ◽  
Elena Kadomtseva ◽  
Grigory Strelnikov
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Normal Stresses ◽  
Reinforcing Bars ◽  
Stress Strain ◽  
Stress Strain State ◽  
Tension And Compression ◽  
The Impact

This article is devoted to the stress–strain state (SSS) study of metal and reinforced fiber-reinforced concrete beam under static and shock loading, depending on the bimodularity of the material, the mass of the beam, and the location of the reinforcing bars in zones under tension and compression. It is known that many materials have different tensile and compression properties, but in most cases, this is not taken into account. The calculations were carried out by using load-bearing metal beams made of silumin and steel and reinforced concrete beams under the action of a concentrated force applied in the middle of the span. The impact load is considered as the plastic action of an absolutely rigid body on the elastic system, taking into account the hypothesis of proportionality of the dynamic and static characteristics of the stress–strain state of the body. The dependences of the maximum dynamic normal stresses on the number of locations of reinforcing bars in zones under tension and compression, the bimodularity of the material, and the reduced mass of the beam are obtained. A numerical study of SSS for metal and concrete beams has shown that bimodularity allows the prediction of beam deflections and normal stresses more accurately.

scholarly journals The Stress-Strain State of the Drill String at the Section of the Borehole with a Cavern

2016 ◽  
Vol 5 (2) ◽  
pp. 128
Author(s):  
Ruslan Rachkevych ◽  
Iryna Rachkevych
Keyword(s):  
Cross Section ◽  
Relative Position ◽  
Strain State ◽  
Drill String ◽  
Transverse Load ◽  
Bending Stress ◽  
Stress Strain ◽  
Stress Strain State ◽  
Drill Pipes ◽  
The Cross

<p class="1Body">This study analyses the stress-strain state of a drill string at the section of the borehole with a cavern/chute. The study was conducted to obtain analytical dependencies to determine normal bending stress in the cross section of the drill string and its downforces to the walls of the well. This will allow to compare these values with the critical ones, and draw conclusions about the possibility and duration of the drill string operation under these conditions.</p><p class="1Body">The study is based on modelling the drill string as a beam, which indicates longitudinal and transverse load and deforms in-plane.</p><p class="1Body">The formulas obtained to determine stresses and pressing forces apply to the following cases of the relative position of the drill string in a straight borehole and a curved borehole with a cavern/chute: a – the drill string touches only the bottom of the borehole; b – the drill string touches only the bottom of the borehole and the bottom of the cavern/chute; c –  the drill string touches the top and the bottom of the borehole; d – the drill string touches the top and the bottom of the borehole and the cavern/chute.</p><p class="1Body">The calculations based on the dependencies obtained lead to the following conclusions: a – the cavern/chute in the inclined straight borehole causes bending stress value in the cross section of drill pipes proportional to the fatigue margin of the material; b – the cavern/chute in the curved borehole may increase normal bending stress in the cross section of the borehole up to five times.</p>

scholarly journals Elaboration of testing technique of flat slabs on punching shear strength using finite element modeling

2018 ◽  
Vol 196 ◽  
pp. 02048
Author(s):  
Valery Filatov ◽  
Zulfat Galyautdinov ◽  
Alexander Suvorov
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Strain State ◽  
Concrete Slabs ◽  
Finite Element Models ◽  
Bending Moments ◽  
Stress Strain ◽  
Stress Strain State ◽  
Reinforced Concrete Slabs

The results of researches on finite-element models of stress-strain state of flat reinforced concrete slabs of beamless frame under punching by columns of square and rectangular cross-section are presented. The purpose of the study was to develop a technique for testing samples plates for punching in the presence of bending moments in a column. The results of the study of deflections of reinforced concrete slabs, the distribution of bending moments in the punching zone of the plate under various loading schemes are presented. Variable parameter was the ratio of the sides of the column cross-section. Comparative analysis of studies results on finite element models has made it possible to choose the optimal variant of applying the load to the test samples, depending on the aspect ratio of rectangular section of column. Results of the conducted research will allow simulating the stress-strain state in the punching zone of natural reinforced concrete slabs of monolithic beamless frame during the test of samples.

scholarly journals DEFORMATION ANALYSIS OF LAYERED REINFORCED CONCRETE - FOAM CONCRETE FLOOR SLABS

2020 ◽  
Vol 60 (4) ◽  
pp. 324-337
Author(s):  
Oksana Lytvyniak
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Strain State ◽  
Deformation Analysis ◽  
Calculated Cross Section ◽  
Foam Concrete ◽  
Deformation Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Floor Slabs

This article presents a theoretical study of a stress-strain state of layered reinforced concrete - foam concrete floor slabs (hereinafter called as the LRFCS), with the use of a deformation analysis. Compressive and tensile diagrams of the foam concrete, a tensile diagram of the reinforced concrete and compressive and tensile diagrams of the reinforcement rod are used for the estimation of the stress-strain state of the calculated cross-section of the LRFCS. It should be noted that this article presents the deformation method of loading by the scheme of pure bending for the LRFCS. This deformation method of loading is determined by six shapes of the stress-strain state. These shapes of the stress-strain state are represented by the corresponding distribution diagrams of the relative deformations and the distribution diagrams of internal stresses in the calculated cross-section of the floor slab. Also, this article presents the corresponding equilibrium equations of internal efforts and moments, which act in the calculated cross-section of the floor slab for all shapes of its stress-strain state. Consequently, the mentioned recommendations and mathematical dependencies allow to evaluate the stress-strain state of the LRFCS from its initial loading to its destruction.

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