scholarly journals Pore pressure when compacting two-phase soil

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Elefhan Agakhanov ◽  
Murad Agakhanov
Keyword(s):  
Pore Pressure ◽  
Strain State ◽  
Solid Mechanics ◽  
Water Pressure ◽  
Deformable Solid ◽  
Stress Strain ◽  
Two Phase ◽  
Tangential Stresses ◽  
Stress Strain State ◽  
Special Cases

In modern conditions, in relation to the total amount of accumulated professional knowledge, the volume of active information resources increases, and construction practice is constantly enriched with new experimentally-theoretically based accurate knowledge. Therefore, various programs are widely used when solving problems in ground bases. Despite the fact that modern numerical methods allow solving problems of any complexity, it should be noted that experimental and analytical methods are still relevant, and it is an effective combination of methods that leads to the development of mechanics, an organic combination of experimental research methods with the enormous computational capabilities of modern supercomputers. Methods for modeling the action of bulk forces are widely used in problems of deformable solid mechanics. Many known solutions have limitations and are given for special cases. The authors present the theoretical foundations of the elastic analogy method for modeling the effect of pore pressure on the soil. When posing the question, the following assumption is made that the liquid filling the pores of the soil does not perceive shear deformation. Tangential stresses that occur in the ground are only perceived by the ground skeleton. The water that fills the pores does not resist tangential stresses. In this case, the deformation of the soil skeleton from the action of hydrostatic water pressure, respectively, is a volumetric deformation. In this case, the components of the ball stress tensor are equal to the pore pressure. The article considers the use of the theory of volume forces in modeling the effect of pore pressure in the process of compaction of two-phase soil. In this case, we consider a one-dimensional problem for the case of deformation (compaction) of a two-phase soil layer thickness under the action of a distributed load of constant intensity. We believe that the consolidated layer lies on a rocky undeformable base. The authors consider various drainage conditions for the surfaces of the consolidated layer. Expressions are given for determining stresses and precipitation with creep, for the instantaneous stress-strain state and the final stress-strain state.

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.

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 Application of Numerical Methods for Research of Construction Design of Fastener Fractures

2021 ◽  
Vol 15 (2) ◽  
pp. 178-183
Author(s):  
Leonid V. Kolomiets ◽  
Aleksej Aniskin ◽  
Viktor F. Orobey ◽  
Alexander Daschenko ◽  
Aleksandr M. Lymarenko ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Analytical Method ◽  
Strain State ◽  
General System ◽  
Boundary Elements ◽  
Cauchy Problems ◽  
Deformable Solid ◽  
Stress Strain ◽  
Stress Strain State ◽  
Method Of Boundary Elements

The work uses modern numerical methods of mechanics of a deformable solid to analyze the stress-strain state of orthopedic structures in order to improve them and improve the quality of treatment of patients. Among the many numerical methods, the attention of the authors was drawn to the finite element method and to the numerical and analytical method of boundary elements in the author's edition. Settlement models of both metal apparatuses and parts of a person’s arm with a fracture are constructed. The stress – strain state in various zones of the biomechanical system was calculated. It is shown that the numerical-analytical method of boundary elements allows obtaining more accurate results with fewer equations in the resolution system. It is noted that in the case of the considered biomechanical systems, its elements undergo tension – compression, shear, torsion, and bending. To consider them, solutions are presented for Cauchy problems, which are included in the general system of resolving equations of the MGE. It is shown that, unlike the FEM, the MGE simplifies the algorithm for calculating biomechanical systems. Comparison with the FEM results shows their good agreement, which proves the reliability of the calculation results of both methods.

scholarly journals Derivation of analytical dependencies for determining stiffness parameters of vibration isolators of vibratory machine

2020 ◽  
Vol 6 (3-4) ◽  
pp. 1-8
Author(s):  
Oleksii Lanets ◽  
◽  
Oleksandr Kachur ◽  
Vitaliy Korendiy ◽  
◽  
...  
Keyword(s):  
Computer Simulation ◽  
Large Scale ◽  
Strain State ◽  
Vibration Isolation ◽  
Solid Mechanics ◽  
Machine Building ◽  
Stress Strain ◽  
Vibration Isolators ◽  
Stress Strain State ◽  
Vibratory Equipment

Problem statement. While designing vibration isolators, the essential attention should be paid to the safety factors such as the levels of vibration and noise, as well as to the material and the structure of isolators. In major vibratory technological equipment, there are used full-metal vibration isolators, which can be designed in the form of coil (cylindrical, conical, helico-spiral) or flat (leaf-type, disc-type) springs. The problems of stress-strain analysis of metal springs used for vibration isolation of various vibratory equipment are of urgent interest among the designers and researcher. The engineering techniques of step-by-step calculation of full-metal vibration isolators of different types of vibratory technological machines are not thoroughly presented in the modern information resources. Purpose. The present paper is aimed at developing and implementing the detailed algorithm of determining the stiffness parameters of the metal coil springs used for vibration isolation of large-scale vibratory machines. Methodology. The investigations are carried out using the basic laws and principles of solid mechanics and theory of vibrations. The calculations were conducted using MathCAD software; the computer simulation of the spring’s stress-strain state was performed using SolidWorks software. Findings (results) and originality (novelty). The improved design of the vibratory conveyer-separator is considered. The engineering technique of calculating the passive vibration isolators of various vibratory equipment designed in the form of metal coil springs is developed. The proposed technique is implemented while designing the vibration isolation system of the vibratory conveyer-separator. The system’s operational characteristics are determined, and the computer simulation of the springs stress-strain state is carried out. Practical value. The proposed design of the vibratory conveyer-separator can be implemented in various industries (machine-building, chemical, pharmaceutical, food-processing, construction, mining, metallurgy, textile industries etc.) for conveying different loose, bulky and piecewise products, and separating them into fractions of different sizes. Scopes of further investigations. While carrying out further investigations, it is necessary to analyse the influence of the proposed design of vibratory conveyer-separator on the foundation during its operation, and to consider the necessary of applying the additional fixation systems.

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

Stress-Strain State of a Plastic Layer under Compression by Two Rigid Parallel Rough Plates

2019 ◽  
Vol 946 ◽  
pp. 768-774 ◽  
Author(s):  
Valery L. Dilman ◽  
Tatyana V. Karpeta ◽  
Aws Nedal Dheyab
Keyword(s):  
Free Surface ◽  
Strain State ◽  
Plane Deformation ◽  
Analytic Form ◽  
Analytical Form ◽  
Plastic Layer ◽  
Stress Strain ◽  
Tangential Stresses ◽  
Stress Strain State ◽  
Recurrent Relations

The stress-strain state of a plastic layer under compression by two rigid parallel rough plates under conditions of plane deformation is investigated. The hypothesis of flat sections is used. Tangential stresses are found in the part of the layer under load, as an approximate solution of the system of equations of the stress-strain state of the compressible layer. The solution is obtained in analytical form. On this basis the velocities of the points of the layer are calculated in the analytic form. The size and shape of the free surface are calculated depending on the thickness of the layer. The coefficients of this dependence are determined by recurrent relations. On this basis, an algorithm for finding the shape of a free surface is found. The computational experiments are provided and the results are compared with results obtained with FEM and ANSYS.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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