Development of Methods for Evaluating the Impact of Stress-Strain State Uniformity of Composite Pavements on Road Safety

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.

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Influence of the sequence of erection of build-ings on the formation of the stress-strain state of the system «base-foundation-overhead structures»

Bases and Foundations ◽

10.32347/0475-1132.41.2020.32-44 ◽

2020 ◽

pp. 32-44

Author(s):

Liudmyla Skochko ◽

Artem Shabaltun

Keyword(s):

Strain State ◽

Design Parameters ◽

Soil Base ◽

Stress Strain ◽

High Rise ◽

Stress Strain State ◽

Subsequent Section ◽

The Impact ◽

Ground Structures ◽

Formulation Of Problems

The influence of the order of construction of houses on the formation of the stress-strain state of the system "foundation-foundation-above-ground structures" is investigated For this purpose, several options for setting tasks for the phased construction of multi-section building sections are considered. With this in mind, it should be noted that the construction of each subsequent section has an impact on the built entirely or partially adjacent section. That is why this effect should be investigated to predict how serious this impact may be, and to draw appropriate constructive decisions. Thus, the main objectives of the study are: Creation of SEM without taking into account the stages of construction of the house; Calculation of a house with a phased loading of 5 floors. Taking into account changes in the order of construction of sections; Formation of SEM taking into account the sequence of erection of sections without including the sequence of erection of floors within the boundaries of the current section; Research of the impact of the calculation of sections of a multi-section building without and taking into account the summary of subsequent sections. The research of the impact of the sequence of construction and installation of the object will allow us to assess the stress-strain scheme at all stages of construction, so changes in the behavior of the scheme will be recorded at all stages of construction specified by the designers. To do this, the change in the stress-strain state (VAT) of the system "foundation - foundations - above-ground structures" must be modeled with different options for stages of construction, taking into account the real parameters of the soil base and so on. The interaction of piles in different zones of sections, the work of grids in the foundations of high-rise buildings are considered. The research was carried out with the help of numerical modeling of the system "foundation - foundations - aboveground constructions". The redistribution of forces in the piles depending on the formulation of problems on the stages of construction of sections and design parameters (location of piles in characteristic zones, the influence of the stiffness of the aboveground part on the redistribution of forces). Characteristic zones in the foundation are distinguished: they are central, lateral, angular and especially at the joints of adjacent sections. The redistribution of efforts between piles and a grid is revealed.

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Laws of gas draining in the massif disturbed by mining operations

E3S Web of Conferences ◽

10.1051/e3sconf/201910900047 ◽

2019 ◽

Vol 109 ◽

pp. 00047

Author(s):

Serhii Kurnosov ◽

Volodymyr Zerkal

Keyword(s):

Strain State ◽

Abutment Pressure ◽

Gas Permeability ◽

Experimental Studies ◽

Rock Massif ◽

Gas Release ◽

Mining Operations ◽

Stress Strain ◽

Stress Strain State ◽

The Impact

A method for calculating gas permeability of the rock massif depending on its stress-strain state is presented. By using methods of the mine experimental studies, influence of mining operations in the adjacent long walls on intensity of gas release from the previously worked-out long-pillar was determined, as well as impact of the massif stress-strain state on efficiency of the drainage boreholes. Formulas were obtained for calculating coefficients of the impact of zones with static and dynamic abutment pressure on intensity of gas draining in the previously worked-out long-pillar.

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Investigation of the Influence of Geometric and Technological Factors on the Stress-Strain State of Metal in the Implementation of the Combined Rolling-Pressing Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.1918 ◽

2014 ◽

Vol 936 ◽

pp. 1918-1924 ◽

Cited By ~ 4

Author(s):

Sergey Lezhnev ◽

Eugeny Panin

Keyword(s):

Metal Forming ◽

Strain State ◽

New Technology ◽

Grain Structure ◽

Stress Strain ◽

Technological Factors ◽

Stress Strain State ◽

Fine Grain ◽

The Impact

In the development of new technology metal forming the main purpose is improvement the quality of the source material. The main aspect of quality improvement is increasing the strength characteristics. Often to increase the strength of deformable metal should be given reduced grain structure, up to subultra and even nanolevel. There are several ways to obtain sub-ultra-fine-grain structure of metals, and one of those ways is a method of severe plastic deformation (SPD), implemented in the whole volume of the deformable metal.In this work computer modeling was performed of the combined process "rolling-pressing" with the use of grooved rolls and equal channel step matrix with varying basic geometric and technological factors which have a significant impact on the process, what was made for the analysis of the impact of various factors on the stress-strain state of the process.

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Determination of stress-strain state of reinforced slabs from non-linear material taking into account the influence of aggressive environment

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska ◽

10.22630/pniks.2018.27.4.46 ◽

2019 ◽

Vol 27 (4) ◽

pp. 488-503

Author(s):

Alexandr Anatolyevich Treschev ◽

Alexander Anatolyevich Bobryshev ◽

Victor Grigoryevich Telichko ◽

Lenar Nurgaleevich Shafigullin ◽

Alexander Valeryevich Bashkatov

Keyword(s):

Strain State ◽

Mechanical Load ◽

Basic Material ◽

Stress Strain ◽

Plastic Deformations ◽

Aggressive Environment ◽

Stress Strain State ◽

Joint Influence ◽

Non Linear ◽

The Impact

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.

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Prediction of contact-fatigue damage to rails using computational-experimental methods

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2020-86-4-46-55 ◽

2020 ◽

Vol 86 (4) ◽

pp. 46-55

Author(s):

N. A. Makhutov ◽

V. S. Kossov ◽

E. S. Oganyan ◽

G. M. Volokhov ◽

M. N. Ovechnikov ◽

...

Keyword(s):

Fatigue Life ◽

Service Life ◽

Software Package ◽

Strain State ◽

Contact Fatigue ◽

Cumulative Distribution ◽

Stress Strain ◽

Stress Strain State ◽

Contact Fatigue Life ◽

The Impact

Analysis of the operational data related to rails failure showed that contact-fatigue defects consistently hold a prominent place. The goal of the study is to show the possibilities of using modern numerical methods in calculation assessment of the service life of rails before the onset of contact fatigue crack formation on a running surface depending on the values of axial load. To calculate a stress-strain state in the area of contact interaction between the wheel and rail a detailed finite-element model implemented in the MSC. Marc software package is used. The analysis revealed complex multiaxial and non-proportional nature of the stress-strain state. The Brown – Miller multiaxial fatigue model implemented in the MSC. Fatigue software package was taken to determine accumulation of the contact fatigue damages on a rail running surface. The model is based on the assumption that maximum fatigue damages in the metal occur in the area with the maximum shear stress. The impact of normal stresses in this area is also taken into account. The results of a comparative computational analysis of the rail life time confirm that the service life decreases with increasing axial loads, all other conditions being the same. With a share of 20% of freight trains with axle loads of 25 tonf in a daily pattern one should expect a decrease in the contact fatigue life of rails by 3 – 4 %. It is possible to improve the method for prediction of the contact fatigue life of rails in terms of experimental definition of the fatigue and strength characteristics of the rail steel depending on the degree of hardening of the running surface, their probabilistic properties and the use of a cumulative distribution of vertical forces taking into account the structure of the freight traffic passing through the section.

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

Materials ◽

10.3390/ma13071579 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1579 ◽

Cited By ~ 2

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.

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Wave processes in determining mechanical characteristics of soils

E3S Web of Conferences ◽

10.1051/e3sconf/20199704009 ◽

2019 ◽

Vol 97 ◽

pp. 04009 ◽

Cited By ~ 13

Author(s):

Karim Sultanov ◽

Pavel Loginov ◽

Sabida Ismoilova ◽

Zulfiya Salikhova

Keyword(s):

Soil Sample ◽

Strain State ◽

Wave Equations ◽

Mechanical Characteristics ◽

Impact Load ◽

Wave Processes ◽

Stress Strain ◽

Stress Strain State ◽

The Impact ◽

The Relationship

Mechanical characteristics of soils under dynamic and static loads are determined in laboratory conditions on special devices. Dynamic loads in the devices are initiated by an impact on a soil sample. Under the impact the waves are initiated in soil; they significantly affect the stress-strain state of soil samples placed in the device. Depending on the parameters of the impact load in the device, in different sections of soil sample there arise the stress-strain states, different in quality and quantity. Mechanical characteristics of soil, determined by this stress-strain state, also differ. The effect of stress-strain state of soil on its mechanical characteristics can be estimated theoretically. The initiation of the wave process and dynamic stress-strain state in soil sample placed in the device can be theoretically examined in detail. In this regard, the wave problem is set, which corresponds to the statement of experiments on the device of dynamic loading of soil. The law of soil strain is taken as an elastic-viscoplastic one. Numerical solution of wave equations is obtained by the finite difference method. Based on the analysis of stress-strain state of soil in various sections, obtained by numerical calculations, the condition is derived under which the effect of wave processes on mechanical characteristics of soils is eliminated. This condition (formula) establishes the relationship between the wavelength, the velocity of wave propagation in soil, the thickness of the soil sample in the device and the duration of dynamic load.

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STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION

Architecture and Engineering ◽

10.23968/2500-0055-2020-5-4-51-59 ◽

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.

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