Compression of Cylinders of Soft Materials

Abstract

SOME time ago, we proposed an equation¹ to describe the behaviour of soft bodies under compression, with special reference to the compression of cylinders. Whereas for a true fluid we have n = Sσ^-1 t¹, and for an elastic solid n = Sσ^-1 t⁰; we proposed for ‘intermediate’ Ψ = Sσ^-1 t^k where s is shearing stress, σ is shearing strain calculated by the logarithmic formula, t is time of compression, n is viscosity, n is shear modulus, and Ψ was described as the “firmness” and k as “a measure of elasticity”, though we should no longer care to use the latter expression, since such properties as work-hardening and dilatancy would reduce k without increasing the elastic recovery.