and its equivalent strain by the expression t ~eq = leeq ~" 0 In [i] an equation was derived relating eeq to the local characteristics of the solid phase and its rheological properties. However, eeq is a macroscopic quantity because in its determination use is made of an averaging operation. This means that a relationship must exist between eeq and other macroscopic parameters. The relationship between the equivalent deformation rate and the macroscopic dissipative function is established on the basis of V. V.Skorokhod's postulate of uniqueness of the dissipative function [2],