The Influence of Distributed Dislocations on Large Deformations of an Elastic Sphere

Author(s):  
Evgeniya V. Zhbanova ◽  
Leonid M. Zubov
Author(s):  
Evgeniya V. Goloveshkina

The phenomenon of stability loss of a hollow elastic sphere containing distributed dislocations and loaded with external hydrostatic pressure is studied. The study was carried out in the framework of the nonlinear elasticity theory and the continuum theory of continuously distributed dislocations. An exact statement and solution of the stability problem for a three-dimensional elastic body with distributed dislocations are given. The static problem of nonlinear elasticity theory for a body with distributed dislocations is reduced to a system of equations consisting of equilibrium equations, incompatibility equations with a given dislocation density tensor, and constitutive equations of the material. The unperturbed state is caused by external pressure and a spherically symmet-ric distribution of dislocations. For distributed edge dislocations in the framework of a harmonic (semi-linear) mate-rial model, the unperturbed state is defined as an exact spherically symmetric solution to a nonlinear boundary value problem. This solution is valid for any function that characterizes the density of edge dislocations. The perturbed equilibrium state is described by a boundary value problem linearized in the neighborhood of the equilibrium. The analysis of the axisymmetric buckling of the sphere was performed using the bifurcation method. It consists in determining the equilibrium positions of an elastic body, which differ little from the unperturbed state. By solving the linearized problem, the value of the external pressure at which the sphere first loses stability is found. The effect of dislocations on the buckling of thin and thick spherical shells is analyzed.


1991 ◽  
Vol 113 (3) ◽  
pp. 292-295 ◽  
Author(s):  
Y. Tatara ◽  
S. Shima ◽  
J. C. Lucero

This paper presents experimental results of simple compression of a soft rubber sphere in a very large range of forces attaining at 5000 N, presenting calculational results by a set of five equations presented in Part 1. The calculational values of approach, the radius of contact surface, and lateral expansion agree well with the experimental data in the large range of deformations. It is thus verified experimentally that the set of the equations (12), (13), (31), (40), and (43) in Part 1 is approximately valid in large deformations for rubber sphere. Program using a personal computer in calculating five quantities from the five nonlinear equations associated with the five quantities is noted.


1976 ◽  
Vol 4 (4) ◽  
pp. 219-232 ◽  
Author(s):  
Ö. Pósfalvi

Abstract The effective elastic properties of the cord-rubber composite are deduced from the principle of virtual work. Such a composite must be compliant in the noncord directions and therefore undergo large deformations. The Rivlin-Mooney equation is used to derive the effective Poisson's ratio and Young's modulus of the composite and as a basis for their measurement in uniaxial tension.


1994 ◽  
Author(s):  
Raouf Raouf ◽  
Anthony Palazotto
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document