Abstract
The equation of tensile strength proposed by Rumpf was extended to deal with the compacted power bed composed of granules. It was assumed that the cohesive force between granules in a compact body is proportional to the contact area brought about by the contact force. Then the tensile strength of such a granules-bed can be determined by estimating the contact force between granules in the bed. The extended equation shows how the tensile strength depends on the compaction force, the porosity and the granule size.
The equation sufficiently explains the results obtained from the tensile strength test of compacts. The compression test of a single granule was also performed to confirm the relationship between tensile strength characteristics of compact and deformability of granule. Parameter m, one of the two parameters in both equations for the tensile strength of compact and compressive deformation of granule, has almost the same value in both tests as expected. However, the other parameter b is larger in the tensile strength test than in the compression test of a single granule. This discrepancy should be further investigated.
