Aspects of strain measures and strain rates (Q1067833)

In finite homogeneous deformation processes, the principal triad generally rotates with respect to a material element during the deformation. The material derivative of the logarithmic strain is no longer simply related to the rate of deformation tensor, and this is exemplified herein. A mathematical procedure is provided for the analysis and the derivations are formulated using the co-rotational rate technique in hope that this technique may be extended to other applications in future modeling. It will be apparent in the article that the co- rotational rate formulation provides a convenient mathematical procedure for handling problems in finite deformation.