ABSTRACT
In this chapter we consider various definitions and measures of stress tensors. The concept of stress is well defined through the concepts of force and area. In the case of finite deformation the areas in the reference configuration may deform significantly and their orientations may also experience substantial changes during the deformation. Thus care must be taken in defining stress. First we consider some basic concepts without consideration for many other details that are significant when the deformation is finite. We consider the case of infinitesimal deformation in which case x¯i ' xi, i.e. we do not distinguish between the reference and the current configurations. This is helpful in establishing basic definitions. These are subsequently extended for finite deformation using co-and contra-variant bases.
