Feasibility of measuring the pressure vs. volume relationship of compressible solids using a thick-walled cylinder

Abstract

According to the theory of thick-walled cylinder (TWC), the internal radial stress of the cylinder can be determined by measuring the hoop strain at the outer wall of the cylinder. We here investigate the feasibility of measuring the radial stress of compressible solids, such as a powder compact positioned inside of a cylinder, using the theory of TWC. Based on finite element analysis, we have shown that provided the geometry of the TWC is appropriately designed, TWC theory can be utilized up to significant volume strains of the specimen positioned in the TWC. The design guidelines for the geometry (thickness and internal radius) of the TWC are provided from the viewpoints of (1) the maximum magnitude of the volume strain up to which TWC theory is applicable, (2) the maximum measurable radial stress before yielding of the cylinder occurs, and (3) the magnitude of the hoop strain when the internal radial stress of the cylinder is very low, especially at the initial stage of powder compaction.