scholarly journals Stress-strain state of a three-layer rod. Comparison of the results of analytical and numerical calculations with the experiment

2018 ◽  
Vol 196 ◽  
pp. 01057 ◽  
Author(s):  
Nikita Tsybin ◽  
Robert Turusov ◽  
Vladimir Andreev ◽  
Alexey Kolesnikov
Keyword(s):  
Strain State ◽  
Analytical Calculation ◽  
Contact Layer ◽  
Elastic Rods ◽  
Stress Strain ◽  
Anisotropic Elastic Medium ◽  
Tangential Stresses ◽  
Stress Strain State ◽  
Anisotropic Elastic ◽  
Comparison Of The Results

The article deals with the stress-strain state of a three-layer rod under central compression. The results of analytical calculation and numerical calculation (FEM) are compared with experimental data. It is assumed that the interaction of layers is accomplished through a contact layer. The contact layer is considered as a transversally anisotropic elastic medium with such parameters that it can be represented as a set of short elastic rods that are not connected to each other and are normally oriented to the contact surface. Such an assumption allows us to obtain an analytical solution of the problem in a closed form, as well as to avoid infinite tangential stresses at the interface of the layers near the model end. The obtained results of calculations coincide qualitatively and quantitatively with the results of the experiment.

scholarly journals DETERMINATION OF STRESS-STRAIN STATE OF A THREE-LAYER BEAM WITH APPLICATION OF CONTACT LAYER METHOD

Vestnik MGSU ◽  
2016 ◽  
pp. 17-26 ◽  
Author(s):  
Vladimir Igorevich Andreev ◽  
Robert Alekseevich Turusov ◽  
Nikita Yur’evich Tsybin
Keyword(s):  
Experimental Data ◽  
Edge Effect ◽  
Strain State ◽  
Rectangular Cross Section ◽  
Contact Layer ◽  
Theory Of Elasticity ◽  
Stress Strain ◽  
Tangential Stresses ◽  
Stress Strain State ◽  
Layer Method

The article deals with the solution for the stress-strain state of a multilayer composite beam with rectangular cross-section, which is bended by normally distributed load. The intermolecular interaction between layers is accomplished by the contact layer, in which the substances of adhesive and substrate are mixed. We consider the contact layer as a transversal anisotropic medium with such parameters that it can be represented as a set of short elastic rods, which are not connected to each other. For simplicity, we assume that the rods are normally oriented to the contact surface. The contact layer method allows us to solve the problem of determining the concentration of tangential stresses arising at the boundaries between the layers and the corner points, their changes, as well as to determine the physical properties of the contact layer basing on experimental data. Resolving the equations obtained in this article can be used for the solution of many problems of the theory of layered substances. These equations were derived from the fundamental laws of the theory of elasticity and generally accepted hypotheses of the theory of plates for the general case of the bending problem of a multilayer beam with any number of layers. The article deals with the example of the numerical solution of the problem of bending of a three-layer beam. On the basis of this solution the curves were obtained, which reflect the stress-strain state of one of the layers. All these curves have a narrow area of the edge effect. The edge effect is associated with a large gradient tangential stresses in the contact layer. The experimental data suggest that in this zone the destruction of the samples occurs. This fact allows us to say that the equations obtained in this article can be used to construct a theory of the strength layered beams under bending.

Investigation of the stress-strain state of beams with different types of web perforation

2021 ◽  
Vol 103 (3) ◽  
pp. 79-87
Author(s):  
Ivan Pidgurskyi ◽  
Vasyl Slobodian ◽  
Denys Bykiv ◽  
Mykola Pidgurskyi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Analytical Calculation ◽  
Complex Stress ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Advantages And Disadvantages ◽  
Stress Strain State ◽  
Element Method

This article is devoted to evaluating the effectiveness of I-beams with different web perforations: hexagonal, round, oval and elliptical. The technology of manufacturing of castellated beams is described. For the purpose of verification the analytical calculation of the beam with hexagonal web perforation and for comparison the calculation by the finite element method is given. To correctly assess the stress-strain state, the mesh of finite elements in the area of openings was concentrated. The results of maximum normal stresses and strains obtained by different methods were compared with each other and the efficiency of using the finite element method to determine the stress-strain state of castellated beams was proved. In the castellated beams there is a complex stress-strain state, which was confirmed in this work for the most characteristic shapes of openings. Beams with hexagonal, round, oval (horizontal and vertical), elliptical and elliptical (rotated by 45°) openings are considered in the article, their geometric parameters and characteristics as well as advantages and disadvantages are described. Beams with round openings are currently the most widely used. In addition, the parameters that affect the efficiency of castellated beams with oval (horizontal and vertical) and elliptical rotated by 45° openings were identified. In this work, it was found that the shape of the openings significantly affects the stress-strain state of the castellated beams, especially for hexagonal openings, which are mainly used so far. The stress distribution in the first opening for each of the considered types of perforations and the nature of the change of σmax in other openings is shown. The stress-strain state of castellated beams was studied using the finite element method. The results of this study are of practical value because they can be used when arranging the sections and openings of castellated beams.

Flexible bar buckling under short-time and long-term compressions

2020 ◽  
Vol 17 (1) ◽  
pp. 199-210
Author(s):  
Anton Egorov ◽  
Vitaly Egorov
Keyword(s):  
Dynamic Analysis ◽  
Mechanical Behaviour ◽  
Strain State ◽  
Stress Strain ◽  
Content Type ◽  
Stress Strain State ◽  
Bar Buckling ◽  
Comparison Of The Results ◽  
Short Time

PurposeThe purpose of this paper is to expand possibilities of stability computing method when performing a dynamic analysis of bar- or rod-shaped elements for actual structures.Design/methodology/approachThe methodology is based on the changes of stress–strain state of the bar-shaped elements at the moment of buckling. The proposed method is based on three assumptions. Firstly, the spatial stress–strain state is determined in the bar. Secondly, technological deviations inherent in real structures are introduced into the bar. Thirdly, mechanical behaviour of the bar is investigated in the mode of real time, which makes it possible to take into account wave deformation processes in the bar. To implement the suggested method of analysis, LS-DYNA package was selected in a dynamic formulation using solid finite elements.FindingsValidity of the proposed method is shown by an example of dynamic stability analysis of a steel flat thin bar with two types of loads: short-time and long-term axial compressions. Comparison of the results showed different nature of the mechanical behaviour of the bar: wave processes are observed under short-time loading, and continuous monotone ones are stated under long-term loads.Practical implicationsResearch results are applicable in the rocket and space industry.Originality/valueA new computer-based methodology for dynamic analysis of heterogeneous elastic-plastic bar-, rod-shaped structures under shock axial compressive loads is proposed.

scholarly journals Experimental studies of the various soils bedding influence on the stress-strain state of a layered subsoil base of the slab foundation

2021 ◽  
Vol 274 ◽  
pp. 03021
Author(s):  
Lenar Siraziev ◽  
Danil Sergeev
Keyword(s):  
Strain State ◽  
Mutual Influence ◽  
Experimental Studies ◽  
Contact Layer ◽  
Deformation Pattern ◽  
Stress Strain ◽  
Stress Strain State ◽  
Compressive Stresses ◽  
The Individual ◽  
Slab Foundation

The purpose of the study is to reveal the effect of the stress-strain state of the three-layer soil base of the slab foundation with a rigid underlying layer, which is heterogeneous along the depth of the ground. The main results of the study are obtaining relative deformations in the soil massif and the settlement of ground values of each layer. The results of experimental studies are obtained in the form of a deformation pattern of a layered base, distribution graphs of compressive stresses in the soil in depth and in a horizontal plane. The significance of the results achieved for the construction area is to establish the mutual influence of various soils on the stress-strain state of the laminate basement of the slab foundation. The presence of a dense top layer in a laminate base significantly increases its distribution ability. The stress distribution is proportional to the load-carrying capacity of the individual base layers. On the boundary between the layers, a jump in the compressive stresses may occur, which indicates the presence of shear deformations in the contact layer.

scholarly journals APPLICATION OF THE MAPLE PACKAGE FOR CALCULATING THE RIBBED PLATE FOR STRENGTH, TAKING INTO ACCOUNT THE DISCRETE LOCATION OF THE RIBS

2021 ◽  
Vol 1 (74) ◽  
pp. 40-44
Author(s):  
G Malinin
Keyword(s):  
Strain State ◽  
Ritz Method ◽  
Analytical Calculation ◽  
Stress Strain ◽  
Discrete Location ◽  
Stress Strain State ◽  
Cross System ◽  
Maple Package

This paper presents an analytical calculation of the stress-strain state of a ribbed plate supported by a cross system of stiffeners. The calculation was carried out by the Ritz method using the Maple mathematical package

scholarly journals INVESTIGATION OF PERMANENT STRAINS IN NANOMODIFIED COMPOSITES AFTER MOLDING AT ELEVATED TEMPERATURES

2020 ◽  
Vol 17 (34) ◽  
pp. 1055-1073 ◽  
Author(s):  
Arseniy V BABAYTSEV ◽  
Ekaterina L KUZNETSOVA ◽  
Lev N RABINSKIY ◽  
Olga V TUSHAVINA
Keyword(s):  
Residual Stress ◽  
Strain State ◽  
Analytical Calculation ◽  
Experimental Result ◽  
Stress Strain ◽  
Stress Strain State ◽  
Binding Material ◽  
Power Load ◽  
Temperature Load ◽  
Residual Strains

This work investigates the effect of carbon nanomodification on the residual stress-strain state (SSS) after molding. One of the ways to reduce residual stresses and deformities is nanomodification. The main objective was to determine the degree of influence of the nanomodification parameters on the residual SSS. Within the framework of this study, 4 slabs were made. Two slabs are made of a conventional binder with laying [010/9010] and [010/4510] and two slabs of a modified binding material with the same layer structure. For the fabricated plates, deflections were measured on each of the four sides, during which residual strains were obtained in the panels of nanomodified carbon fiber for the considered layings with and without modified binding material. To analyze the residual stress-strain state, a numerical and analytical calculation was performed. The numerical calculation was carried out by means of the finite element method for the case when the slab is fixed at the point of the geometric center, with no power load, and the temperature load is a difference of 100 °C. An analytical calculation was carried out for the case when the slab is free from fastening and external power load, and the temperature load is a difference of 100°C. During the study, variants of the physicomechanical properties of the monolayer were obtained using the Digimat software and the Mori-Tanaka averaging method. The results obtained by analytical and numerical methods have a good correlation between each other, and in the course of comparison with the experiment, a method for calculating the characteristics of the monolayer that was closest to the experimental result was determined. On the basis of the obtained results, conclusions were made on the possibility of reducing residual SSS and deformation in structures with asymmetric reinforcement schemes using a matrix containing carbon nanoparticles.

scholarly journals STUDY OF THE STRESS-STRAIN STATE OF THE "FILLING-TOOTH" SYSTEM IN CERVICAL DEFECTS OF THE TEETH.

2020 ◽  
Vol 20 (4) ◽  
pp. 108-114
Author(s):  
N.N. Brailko ◽  
I.M. Tkachenko
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Vertical Component ◽  
Biomechanical Analysis ◽  
Cervical Region ◽  
Filling Material ◽  
High Quality ◽  
Stress Strain ◽  
Tangential Stresses ◽  
Stress Strain State

The problem of preserving restorations in defects in the cervical region, even with high-quality preparation and restoration, is also relevant in the modern world. The tensions in the teeth lead to the formation of cracks in the enamel and dentin, loss of tightness and marginal adhesion of the fillings, resorption and loss. Therefore, to ensure high-quality results of treatment of hard tissue defects in the cervical region of the teeth, it is appropriate to take into account the physical processes occurring around the "filling-tooth" system, namely, the stress-strain state. To assess the stress-strain state of the coronal part of the teeth with restorations, given the tightness and extreme cumbersomeness of using traditional analytical methods of theoretical mechanics and resistance of materials through a variety of geometric shapes and physical and mechanical characteristics of hard tissues of the dentition and filling material, it seems most appropriate to conduct research with using finite element modeling. The purpose of this biomechanical analysis is to study the influence of the size and location of defects of the cervical region on the stress-strain state of the obturation material in cases of restoration of these defects. Biomechanical analysis of the stress-strain state of the filling material was performed using elastic three-dimensional models of single-rooted teeth (first premolar and canine) fixed in the alveolar bone with periodontal ligaments surrounding the tooth root. Mathematical modeling was performed using the well-known modeling package and finite element analysis FEMAP 10.2.0, designed for implementation in the Windows environment on a personal computer. In order to reduce the number of finite elements, and as a consequence, reduce the amount of computational procedures and the amount of time spent on the calculation while increasing the accuracy of calculations, further research seems appropriate not on the full model of the mandible, but on its fragment isolated from the mandible. the first premolar and canine. Biomechanical analysis of the stress-strain state was performed on a fragment of the jawbone with overall dimensions of the cross section, which corresponds to some average dimensions: height h = 22 mm and width b = 16 mm. The program, which is used to build and analyze the considered models on the basis of the finite element procedure, determines the displacement of each node of the finite element along three coordinate axes, normal and tangential stresses, as well as equivalent Huber-Mises stresses. As the main criteria for assessing the stress-strain state of the obturation material, it is advisable to take the maximum values of tangential stresses at the adhesion boundary, which shift the filling material relative to the boundary of the restored cavity and thus determine the strength of the adhesive layer and, consequently, durability. The most unfavorable of the considered combinations of loads was the joint action of the vertical component of the load with the horizontal in the lingual-vestibular direction (corresponding to the maximum value of tangential stresses at the adhesion of the filling material) in the localization of restoration on the vestibular surface in the cervical premolar. When localizing the restoration on the oral side of the cervical premolar, the most unfavorable of the considered combinations of loads was the joint action of the vertical component of the load with the horizontal in the vestibular-lingual direction. Thus, the direction of action of the horizontal component of the functional load, in the most unfavorable combination with the vertical, is determined by the localization of the restoration on the lateral surface of the premolar.

scholarly journals Theory of “dissolution” and “condensation” of the physical geometric characteristics of an arbitrary cross-section under the action of torsion with bending

2019 ◽  
Vol 15 (4) ◽  
pp. 261-270
Author(s):  
Vladimir I. Kolchunov ◽  
Aleksej I. Demyanov ◽  
Nikolay V. Naumov
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Strain State ◽  
Rectangular Cross Section ◽  
Arbitrary Cross Section ◽  
Large Circle ◽  
Stress Strain ◽  
Cross Sectional ◽  
Tangential Stresses ◽  
Stress Strain State

Aim of research - to continue the development of methods for determining the stress-strain state of rods during torsion using materials resistance methods. Methods. A new approach for determining tangential torsional stresses for arbitrary cross sectional rods, based on simplified assumptions of material resistance, is proposed. The main feature of this approach is the approximation of rectangular or any complex cross section of reinforced concrete structures by describing a large circle around the cross section and splitting it into small squares with circles inscribed into them. Results. Three theorems have been formulated, the first of which relates the accumulation of tangential stresses (increments) from the edges of a rectangle to the middle of a rectangular section with the formula for determining tangent stresses for round sections. The second theorem allows to establish a connection between the tangential stresses calculated for each of the small squares-circles and the tangent stresses of the large circle through their increments. The third theorem makes it possible to find tangential stresses for each of the small square circles. The proposed approach allows to remove the need to use special tables for the calculation and not only in the elastic stage. It also makes it possible to separate the stress-strain state in the whole set of round cross-sections from the additional field caused by the deplanation of the rectangular cross-section. In addition, the proposed approach makes it possible to take into account the concentration of angular deformations in the incoming angles and other places with changing geometric parameters.

scholarly journals Development of a technique for computer simulation of the stress state of the drive drum shell of a belt conveyor to optimize its design parameters

2021 ◽  
Vol 2 (7 (110)) ◽  
pp. 31-39
Author(s):  
Olzhas Jassinbekov ◽  
Madina Isametova ◽  
Gabit Kaldan
Keyword(s):  
Computer Simulation ◽  
Strain State ◽  
Computer Calculation ◽  
Variable Pressure ◽  
Design Parameters ◽  
Shear Stresses ◽  
Stress Strain ◽  
Tangential Stresses ◽  
Stress Strain State ◽  
Angle Of Rotation

The paper considers the method of computer simulation of the stress-strain state of the drive drum shell in the NASTRAN integrated environment. Due to the complexity of determining stresses and deformations in the drum sections by the analytical method, it is proposed to solve this important problem using the numerical finite-element method. At the preliminary stage of computer modeling, a mechanical design scheme was developed, including a variable pressure that changes depending on the angle of rotation of the drum, the deterministic relations describing the variable force factors are based on the Euler ratio. It is also proposed to take into account the pressure from the variable friction force, which depends on the changing coefficient of adhesion of the belt to the drum. As a result of the computer calculation, the equivalent Mises stresses of 65 MPa were determined, the safety factor was 4.2 and the components of the tangential stresses were determined using the stress tensor marker, the shear stress reached the level τ=16 MPa for fabric tape and τ=3.14 MPa for rubber tape. According to the results of the calculation, the dependence of the tangential stresses on the angle of rotation of the drum was constructed. A diagram of the change in the component of tangential stresses along the forming shell of the drum was constructed. Analysis of stress-strain state allowed us to determine the factor of safety of the drum shell. Based on the analysis of equivalent stresses, it is proposed to further calculate the durability of the drum using the method of long-term fatigue. The computer calculation of shear stresses in the component allows choosing the rational parameters of the lining, based on such indicators as peel strength and break, as well as determining the angle 61° of the slab lining required to improve the reliability and traction ability of the pipeline

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