Fragmentation of Brittle Spheres Compressed Statically and Dynamically Between Two Rigid Platens

摘要

For static compressions of spheres, a new stress analysis for isotropic elastic spheres compressed between two rigid platens is proposed by incorporating the Hertz contact stress with the classical solution by Hiramatsu and Oka (1966). The predictions of the failure load for various sizes and strengths of spheres agree very well with our experiments. For dynamic compressions of spheres, it is found that although the maximum contact force is larger in the static case than that in the dynamic case, the energy required to fracture the sphere is larger under the dynamic situation. By comparing the static and dynamic tests, we found that the dynamic impact energy required to fracture a sphere can be approximately as 1.5 times of that for the static test. As expected, the dynamic impact energy increases monotonically with the size and strength of the spheres. However, the contact time at failure does not exhibit a clear trend with the changes in size and strength of the spheres.