Influence of Finite-Length Plate Proximity on Vortex-Induced Vibrations of Elastic Cable

Vortex-induced vibrations of an elastic cylinder near a finite-length plate are experimentally investigated. A rubber cylinder of diameter D was spanned in the test section of a wind tunnel near a plate of length nearly 6D. The oscillation amplitude peak for a single cylinder was 0.3D, Reynolds number for oscillating peak-amplitude regime based on the cylinder diameter was in the range 180...260. The oscillation amplitude ratio A/D appeared to decrease with the reduction of the gap ratio G/D between the cylinder surface and the plate for the cylinder located sufficiently upstream from the plate trailing edge. However, for the cylinder location at the same level or downstream from the plate trailing edge, there are regions of essentially larger oscillation amplitude compared to the isolated cylinder case. Maximum amplitude increase by 39% was obtained.

The problem of the interaction of a conical indenter with an elastic cylinder

В данной работе исследуется поведение эластомера при взаимодействии с жестким штампом, вершина которого имеет форму конуса. В качестве определяющих соотношений используются модель материала Генки и ее обобщение для описания физически-нелинейного отклика. Проведено сравнение результатов численного решения с кривыми, полученными из рассмотрения поставленной задачи в рамках линейной модели с использованием теории Герца. В работах [10, 11] показана принципиальная возможность определения параметров модели гиперупругости на основе определяющих соотношений Генки-Мурнагана из экспериментов по индентированию сферическим штампом. Результаты, полученные в данной работе, могут быть использованы для построения методики определения параметров нелинейно-упругой модели из экспериментов по индентированию коническим штампом. In this paper, we investigate the behavior of an elastomer when interacting with a rigid punch, the top of which is cone-shaped. Hencky’s material model and its generalization to describe the physically nonlinear response are used as the constitutive relations. The results of the numerical solution are compared with the curves obtained from considering the problem in the framework of a linear model using the Hertz theory. The works [10, 11] show the fundamental possibility of determining the parameters of the hyperelasticity model based on the Hencky- Murnaghan constitutive relations from experiments on indentation with a spherical stamp. The results obtained in this work can be used to construct a method for determining the parameters of a nonlinear elastic model from experiments on indentation with a conical stamp.

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

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.

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

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.