Local nature of the stress-strain state of a composite material subjected to frictional forces

1995 ◽  
Vol 33 (9-10) ◽  
pp. 496-500 ◽  
Author(s):  
M. V. Kindrachuk ◽  
Yu. Ya. Dushek ◽  
M. V. Luchka
Keyword(s):  
Composite Material ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State ◽  
Frictional Forces ◽  
Local Nature

Stress and Strain Analysis of Three-Layer Composites with Interlayer Slip under Hygrothermal Loads

2006 ◽  
Vol 113 ◽  
pp. 565-570
Author(s):  
D. Zabulionis
Keyword(s):  
Composite Material ◽  
Exact Solutions ◽  
Strain State ◽  
Strain Analysis ◽  
Stress And Strain ◽  
Function Form ◽  
Stress Strain ◽  
Stress Strain State ◽  
Layer Composite ◽  
Interlayer Slip

This article deals with the stress and strain state of a three–layer composite material with interlayer slip subjected to hygrothermal loading. The exact solutions in an explicit function form that allows one to determine the stress-strain state and deflection of three–layer composite subjected to hygrothermal loading and by taking this into consideration the interlayer slip is proposed.

scholarly journals Stress-Strain State of the Bottom of the Casing String in the Horizontal Well

2019 ◽  
pp. 54-64
Author(s):  
І. І. Paliichuk
Keyword(s):  
Differential Equation ◽  
Strain State ◽  
Horizontal Well ◽  
Iterative Solution ◽  
Algebraic Equations ◽  
Stress Strain ◽  
Horizontal Pipe ◽  
Stress Strain State ◽  
Axial Forces ◽  
Frictional Forces

The purpose of the work is to develop the method for calculating the stress-strain state parameters of the bottom of the casing which is lowered into a horizontal well during its construction. When pushed into a well, a long casing string on the supports experiences cross bendings and bucklings which are caused by its own gravity and frictional forces created by axial forces of string compression. The latter are variables in length and depend on the reactions at the supports. The problem is solved by integrating the differential equation of the long rod buckling caused by its own gravity. In a first approximation, the reactions at the supports are found out disregard-ing the axial forces of friction. The author finds the general solution of the basic differential equation of horizontal pipe column deformations taking into account friction and axial forces acting during its lowering. It forms the basis for calculating bucklings and bendings, angles of rod rotation, its inner bending moments and cross forces at the sections between the supports. Geometric and power parameters of pipe deformations at the sections between the supports can be determined using the system of equations of the compatibleness of the angles of rotation and the  support moments equilibrium. These equations contain axial force parameters, which can also be derived using the suggested system of algebraic equations. The solution of the problem becomes possible due to adding the transverse force equations to this system. These equations are obtained on the basis of the established relation between transverse and axial forces in the column and reactions and friction at the supports. It allows determining the axial compressive forces simultaneously. The method of linearization of the algebraic equations system and its iterative solution with high accuracy is developed. Due to the value of axial forces, calculated in a first approxi-mation, the system becomes linear, and its iterative solution allows finding the desired parameters with high accu-racy. The obtained results take into account the requirements to the construction technology of a horizontal well. The author considers the deviations of the well direction from the horizontal on the change of the stress-strain state of the casing. The paper offers the formulae to calculate the optimal distance between the casing centralizers as well as solves the problem of its reverse motion. The author takes into consideration additional moments of frictional forces affecting the casing centralizers. The obtained results might serve for the analysis of the stress-strain state of the casing column in the technological process of the horizontal well construction which makes it possible to increase its reliability and lifelength.

scholarly journals NONLENEAR DEFORMATION OF GRANULAR COMPOSITES

2020 ◽  
pp. 121-131
Author(s):  
E. Shikula
Keyword(s):  
Composite Material ◽  
Strain State ◽  
Effective Properties ◽  
Physical Nonlinearity ◽  
Theory Of Elasticity ◽  
Layered Composite ◽  
Layered Material ◽  
Stress Strain ◽  
Stress Strain State ◽  
Volumetric Content

The model of nonlinear deformation of a layered material with physically nonlinear layers is proposed. The laminate is considered a two-component material with random layers. The basis is the stochastic differential equations of the physically nonlinear theory of elasticity L.P. Khoroshun. The solution to the problem of the stress-strain state and effective properties of the composite material is constructed by the averaging method. An algorithm for determining the effective deformable properties of a layered material with physically nonlinear layers has been developed. The solution of nonlinear equations taking into account their physical nonlinearity is constructed by an iterative method. The law of the relationship between macrostresses and macrostrains in a layered material and the dependence of average strains and stresses in its layers on macrostrains has been established. Curves of material deformation are plotted for different values of the volumetric content of its filler. The dependence of the effective deformative properties of the laminated material on the volumetric content of the filler has been studied. The effect of nonlinearity of layers on the deformation of a layered composite material is investigated. It was found that the nonlinearity of the layers significantly affects the effective deformative properties and the stress-strain state of laminated materials.

Research on Nonlinear Deformation and Stability of an Aircraft Fuselage Composite Section under Transverse Bending

2021 ◽  
pp. 106-116
Author(s):  
L.P. Zheleznov ◽  
A.N. Seriosnov
Keyword(s):  
Composite Material ◽  
Strain State ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Aircraft Fuselage ◽  
Stress Strain State ◽  
Classical Formulation ◽  
Reinforced Composite ◽  
Transverse Bending ◽  
Composite Section

Currently, there is a lack of studies on the strength and stability of reinforced composite shells, taking into account the momentness and nonlinearity of the initial stress-strain state. Most of the known solutions to the shells stability problems are obtained by analytical and numerical methods, as a rule, in the linear approximation, i.e. in the classical formulation. A developed technique is proposed implementing the finite element method for solving the problems of strength and stability of discrete-reinforced cylindrical shells made of the composite material, taking into account the momentness and nonlinearity of their subcritical stress-strain state. The transverse bending stability of the reinforced aircraft fuselage compartment made of composite material has been investigated. The effect of deformation nonlinearity, stiffness of stringer set, shell thickness on critical loads of the shell instability has been determined.

scholarly journals COMPLETE SOLUTION OF LAME PROBLEM FOR A THICK-WALLED COMPOSITE NONLINEARLY DEFORMABLE CYLINDER

2020 ◽  
Vol 2 (4) ◽  
pp. 64-72
Author(s):  
A. Kravchuk ◽  
A. Kravchuk ◽  
S. Lopatin
Keyword(s):  
Composite Material ◽  
Boundary Value Problem ◽  
Strain State ◽  
Complete Solution ◽  
Boundary Value ◽  
Effective Characteristics ◽  
Composite Cylinder ◽  
Stress Strain ◽  
Stress Strain State ◽  
Lamé Problem

the paper deals with the boundary value problem for the nonlinearly deformable composite cylinder with different types of boundary conditions. The stresses and displacements on both boundaries of the cylinder are constant, so their boundary average values for any area are constant and equal to the initial values. It should be noticed, that the solution of the boundary value problem is obtained without using nonlocal hypotheses about the composite material volume smallness by the angle for which the effective characteristics are calculated. In addition, the assumption of the composite material element smallness in the radial direction with respect to the thickness of the cylinder is used. It is established, that there is no possibility to consider plane stress state and plane strain of the cylinder separately from each other. Both of these states should be studied for analysis of stress-strain state according to Voigt and Reuss hypotheses. It is also shown that the solution of the Lame problem for a cylinder, which is derived, based on Voigt and Reuss hypotheses, is self-sufficient. Formulas, which describe stress-strain state of the composite cylinder, are derived based on this approximation.

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