scholarly journals CALCULATION OF STRESS-DEFORMED STATE OF ELASTIC CYLINDERS UNDER TEMPERATURE AND HUMIDITY IMPACT

2020 ◽  
Vol 3 (3) ◽  
pp. 94-112
Author(s):  
Vyacheslav Ogarkov ◽  
Aleksei Aksenov ◽  
Sergei Malyukov ◽  
Margarita Malyukova
Keyword(s):  
Physical Meaning ◽  
Practical Problem ◽  
Exact Analytical Solution ◽  
Plane Deformation ◽  
Elastic Cylinder ◽  
Cylindrical Shape ◽  
Temperature And Humidity ◽  
Deformed State ◽  
Elastic Cylinders ◽  
Modified Wood

The actual scientific and practical problem of plane deformation of an elastic cylinder under conditions of temperature and humidity is considered. Various pipes, shafts, plain bearings, bushings from natural and modified wood, etc. have a cylindrical shape. An exact analytical solution of this problem is given for an isotropic cylinder in the case of stationary temperature and humidity exposure. All formulas for stresses and strains and stresses contain mechanical and thermophysical constants, which corresponds to the physical meaning. It is proved that the use of classical methods for solving this problem through the potentials of stresses and displacements leads to an undesirable result in which stresses or deformations do not depend on the thermophysical constant C_2, which contradicts the physical meaning.

scholarly journals POLAR-SYMMETRIC DEFORMATION OF AN ELASTIC CYLINDER UNDER TEMPERATURE-HUMIDITY EXPOSURE

2020 ◽  
Vol 3 (3) ◽  
pp. 81-93
Author(s):  
Vyacheslav Ogarkov ◽  
Aleksei Aksenov ◽  
Sergei Malyukov
Keyword(s):  
Analytical Solution ◽  
Radial Displacement ◽  
Exact Analytical Solution ◽  
Technical Problem ◽  
Incompressible Material ◽  
Elastic Cylinder ◽  
Symmetric Deformation ◽  
Temperature And Humidity ◽  
Special Case

The actual scientific and technical problem of polar-symmetric deformation of an elastic cylinder under conditions of temperature and humidity influences is considered. An exact analytical solution to this problem is obtained with the determination of unambiguous expressions for stresses, deformations and radial displacement. The obtained solution allows solving this problem for an incompressible material with μ = 1/2 as a special case.

scholarly journals Stress Resultants and Out-of-Plane Deformations in Stiff Rings Attached to Elastic Cylinders and Subject to Concentrated Loads

1971 ◽  
Vol 93 (3) ◽  
pp. 835-844 ◽  
Author(s):  
Bernard W. Shaffer ◽  
Eric E. Ungar
Keyword(s):  
Cross Sections ◽  
Bending Moment ◽  
Elastic Cylinder ◽  
Concentrated Force ◽  
Direction Parallel ◽  
Out Of Plane ◽  
Elastic Cylinders ◽  
Special Case ◽  
Radial Axis ◽  
Plane Deformations

Expressions are derived which give the internal loads and deformations of a relatively stiff ring which is mounted on an elastic cylinder. Three basic types of loads acting on the ring are considered: a concentrated force acting in the direction parallel to the axis of the cylinder, a bending moment acting about a radial axis, and a bending moment acting about a tangential axis. The entire problem is first analyzed for the general case in which the centers of twist of the ring cross sections do not coincide with the mid-surface of the cylinder, and then also developed for the special case where these do coincide. An illustrative example is presented which gives an indication of the effect of the lack of coincidence of the centers of twist of the ring and the cylinder mid-surface.

Direct Discrete Method for Neutronic Calculations

2002 ◽  
Author(s):  
Naser Vosoughi ◽  
Majid Shahriari ◽  
Ali Akbar Salehi
Keyword(s):  
Differential Equation ◽  
Boundary Conditions ◽  
Balance Equation ◽  
Physical Meaning ◽  
Neutron Transport ◽  
Direct Method ◽  
Cylindrical Shape ◽  
Neutron Transport Equation ◽  
Discrete Method ◽  
Discrete Equations

The objective of this paper is to introduce a new direct method for neutronic calculations. This method which is named Direct Discrete Method, is simpler than the neutron Transport equation and also more compatible with physical meaning of problems. This method is based on physic of problem and with meshing of the desired geometry, writing the balance equation for each mesh intervals and with notice to the conjunction between these mesh intervals, produce the final discrete equations series without production of neutron transport differential equation and mandatory passing from differential equation bridge. We have produced neutron discrete equations for a cylindrical shape with two boundary conditions in one group energy. The correction of the results from this method are tested with MCNP-4B code execution.

Optimization of the geometry of specimens with transversal groove for materials with initial anisotropy

2021 ◽  
Vol 87 (1) ◽  
pp. 61-67
Author(s):  
V. V. Eliseev ◽  
L. V. Khlivnenko ◽  
A. M. Goltsev
Keyword(s):  
Software Package ◽  
Shear Fracture ◽  
Plane Deformation ◽  
Rolling Direction ◽  
Test Scheme ◽  
Initial Anisotropy ◽  
Deformed State ◽  
Abaqus Software ◽  
Principal Strains

The goal of the study is determination of the optimal geometric dimensions of rectangular anisotropic specimens with a transverse groove when tested for uniaxial tension under conditions close to plane deformation. A test scheme in which the shear fracture mechanism is implemented in the center of the groove under conditions of plane deformation is presented. The optimal geometric dimensions of the specimen (namely, the depth, width and length of the transversal groove) were determined proceeding from numerical simulation of the experiment in the ABAQUS software package in the Explicit mode. It is shown that the initial anisotropy of the material significantly affects the deformed state in the groove. The larger the ratio of the Lankford coefficients along the rolling direction and across this direction, the closer the deformed state in the groove to the plane deformation. It is also shown that change in the geometry of the specimen with a transverse groove can provide better results in implementation of the plane deformation in the region of specimen fracture. The value of the parameter of the deformed state approaches zero when the thickness and width of the groove decrease, as well as when the width of the specimen increases. It is shown that the possibility of forming plane deformation in the groove due to the choice of specimen geometry is limited from above for any initial anisotropy. A moment of «saturation» is observed, at which the ratio of principal strains in the center of the groove does not go any further to zero despite further change in the geometry. A table of geometric dimensions of rectangular specimens with a transverse groove recommended for tensile testing under conditions of plane deformation for all types of anisotropic and isotropic sheet materials is presented.

Research of stamping of unequal channel bars. Part 4. Deformed state of the workpiece when extruding channels. 3. Consideration of hardening

2021 ◽  
pp. 74-76
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plane Deformation ◽  
Extrusion Process ◽  
Deformable Material ◽  
Die Forging ◽  
Deformed State

Formulas are derived to take into account the effect of hardening of a deformable material on stresses and force parameters of the extrusion process, as well as on the results of shaping. Keywords: die forging, extrusion, misalignment, punch, matrix, plane deformation, accumulated deformations, hardening [email protected]

scholarly journals Harmonic Standing-Wave Excitations of Simply-Supported Isotropic Solid Elastic Circular Cylinders: Exact 3D Linear Elastodynamic Response

2020 ◽  
Vol 12 (06) ◽  
pp. 2050060
Author(s):  
Jamal Sakhr ◽  
Blaine A. Chronik
Keyword(s):  
Analytical Solution ◽  
Standing Wave ◽  
Forced Vibration ◽  
Elastic Cylinder ◽  
Wave Number ◽  
Mode Shapes ◽  
Simply Supported ◽  
Isotropic Solid ◽  
Elastic Cylinders ◽  
Vibration Problems

The vibration of a solid elastic cylinder is one of the classical applied problems of elastodynamics. Many fundamental forced-vibration problems involving solid elastic cylinders have not yet been studied or solved using the full three-dimensional (3D) theory of linear elasticity. One such problem is the steady-state forced-vibration response of a simply-supported isotropic solid elastic circular cylinder subjected to two-dimensional harmonic standing-wave excitations on its curved surface. In this paper, we exploit certain recently-obtained particular solutions to the Navier–Lamé equation and exact matrix algebra to construct an exact closed-form 3D elastodynamic solution to the problem. The method of solution is direct and demonstrates a general approach that can be applied to solve other similar forced-vibration problems involving elastic cylinders. The obtained analytical solution is then applied to a specific numerical example, where it is used to determine the frequency response of the displacement field in some low wave number excitation cases. In each case, the solution generates a series of resonances that are in exact correspondence with a subset of the natural frequencies of the simply-supported cylinder. The analytical solution is also used to compute the resonant mode shapes in some selected asymmetric excitation cases. The studied problem is of general interest both as an exactly-solvable 3D elastodynamics problem and as a benchmark forced-vibration problem involving a solid elastic cylinder.

Devices for testing of the friction with the bearing from the modified wood

2015 ◽  
Vol 5 (4) ◽  
pp. 188-201 ◽  
Author(s):  
Аксенов ◽  
Aleksey Aksenov ◽  
Малюков ◽  
Sergey Malyukov
Keyword(s):  
Automatic Control ◽  
Ambient Air ◽  
Combined Effect ◽  
Test Device ◽  
Control Units ◽  
Temperature And Humidity ◽  
Modified Wood

Setting for research combined effect of heat and cold on the performance of the modified wood bearings with automatic control units has been presented. It allows testing of the bearing with variable sliding speeds (60 to 760 rev / min) and loads (300 to 3000 kgf) in different environments and under dif-ferent temperature and humidity of the ambient air parameters. Kinematics of the test device with a de-tailed description of the device and the principle of work has been shown. The technical characteristics of the apparatus of heat - cold has been presented.

Research of dependence of tribological properties of highly loaded bearings made of modified wood

2016 ◽  
Vol 6 (1) ◽  
pp. 168-185 ◽  
Author(s):  
Аксенов ◽  
Aleksey Aksenov ◽  
Малюков ◽  
Sergey Malyukov
Keyword(s):  
Thermal Conductivity ◽  
Heat Resistance ◽  
Tribological Properties ◽  
Operating Temperature ◽  
Sliding Bearings ◽  
Low Thermal Conductivity ◽  
Friction Units ◽  
Temperature And Humidity ◽  
Highly Loaded ◽  
Modified Wood

Analysis of the widespread use of modified wood in friction units of various machines has been. It has been shown that the modified wood is significantly changing its mechanical proper-ties, depending on the operating temperature and humidity. Low thermal conductivity and heat resistance of the modified wood requires a mandatory settlement information about temperature in friction sliding bearings. It was revealed that the underestimation of the temperature and hu-midity stresses can lead to intensive wear, and in some cases, to the destruction of the slide bearings.

Contact Stresses Between Layered Elastic Cylinders

1984 ◽  
Vol 106 (3) ◽  
pp. 396-404 ◽  
Author(s):  
R. Solecki ◽  
Y. Ohgushi
Keyword(s):  
Integral Equation ◽  
Pressure Distribution ◽  
Elastic Cylinder ◽  
Algebraic Equations ◽  
Contact Pressure Distribution ◽  
Rigid Cylinder ◽  
Linear Algebraic Equations ◽  
Static Contact ◽  
Contact Width ◽  
Elastic Cylinders

Frictionless static contact between two layered elastic cylinders is examined. Local curvature of the the contacting surfaces is taken into account. Green’s function is derived and utilized to reduce the contact problem to Fredholm integral equation of the first kind with unknown contact width, unknown contact pressure distribution and unknown normal approach. Solution of this integral equation is obtained in the form of an infinite system of linear algebraic equations with the aid of Fourier transformation. The resulting equations are solved to give the pressure distribution and the normal approach for assumed contact width. Numerical results of two examples are presented: one in which an elastic layer bonded to a rigid cylinder is indented by another rigid cylinder, and, a second in which a layered elastic cylinder is indented by another layered elastic cylinder. The results obtained in the first example are compared with analytical solutions and with experimental data known from the literature.

The compression of anisotropic fibre monofilaments. II

1966 ◽  
Vol 291 (1425) ◽  
pp. 267-278 ◽  
Keyword(s):  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Synthetic Fibre ◽  
Transversely Isotropic ◽  
Elastic Cylinder ◽  
Poisson's Ratio ◽  
Elastic Cylinders ◽  
Complete Specification ◽  
Microscope Stage

A synthetic fibre monofilament was compressed between transparent flats mounted on a microscope stage. The change in the monofilament diameter parallel to the plane of the flats was determined as a function of load for polyethylene terephthalate and nylon monofilaments. These monofilaments can be regarded as transversely isotropic elastic cylinders. A theoretical solution was therefore derived for the change in diameter of a transversely isotropic elastic cylinder compressed between two rigid parallel planes. The solution for the change in diameter in terms of the elastic constants and the applied load was verified experimentally. Measurements of the change in diameter as a function of load were combined with measurements of the width of the contact zone between the cylinder and the upper transparent flat. The results together with subsidiary measurements of extensional compliance and extensional Poisson’s ratio were then used to derive the transverse compliance and the transverse Poisson’s ratio of the monofilaments. This compression problem provides the first reported determination of the transverse Poisson’s ratio for synthetic fibre monofilaments. It is therefore now possible to obtain all five independent elastic constants, four of which are related to the measurements described in this paper. For the sake of completeness, results for the torsional compliance of these monofilaments have been undertaken thus giving complete specification of the elastic properties.

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