Displacements and Finite-Strain Fields in a Sphere Subjected to Large Deformations

摘要

As part of an extensive investigation on experimental methods to determine displacements, strains and stresses in large deformation problems, this paper presents the three-dimensional solution for displacements and strains for the case of a solid sphere diametrically loaded to several levels of loads. A polyurethane rubber was used to make the sphere, and grids and moire gratings printed on a meridian plane, were used to measure displacements. Strains were obtained by photographical differentiation of the field of displacements. The solution for infinitesimal strains is compared to a previous solution by one of the authors. The maximum applied vertical displacement reduced the diameter of the sphere by 27 percent. Results are presented in terms of Eulerian strains, in the Eulerian description and in terms of natural strains. (Author)