Abstract
In this paper, experimental methods and results are presented for deformations of solid rubber spheres under diametral compression in a very wide range of forces from 0. 5 N to 5 000 N, for five rubber spheres of the same size and different stiffnesses. The experimental results show some phenomena of large deformations beyond the Hertz theory. By measuring the Young modulus of each rubber sphere, three displacements (approach, contact radius, and lateral extension) against force are calculated by the previous and new theories presented in Part I and are compared with the experimental data. The recent theory I and the new theory II are both compatible with the data. Profiles of compressed shapes of the rubber spheres are measured and compared with those predicted by theories I and II. It is concluded that the two theories, I and II are approximately valid for the compression of rubber spheres.