NATURAL STRAIN

The purpose of this paper is to present a consistent and thorough deve lopment of the strain and strain-rate measures afiliated with Hencky. Natural measures for strain and strain-rate, as I refer to them, are f irst expressed in terms of the fundamental body-metric tensors of Lodg e. These strain and strain-race measures are mixed tensor fields. They are mapped from the body to space in both the Eulerian and Lagrangian configurations, and then transformed from general to Cartesian fields . There they are compared with the various strain and strain-rate meas ures found in the literature. A simple Cartesian description for Henck y strain-rate in the Lagrangian stare is obtained.