Chapter 1 - Effective stress

Abstract

In this chapter, the concept of effective stress is introduced. Two major scalar damage variables used by researchers today are introduced first. For other damage variables, the reader is advised to check the work of Lemaitre (1984, 1992) and Lemaitre and Chaboche (1990). The first scalar damage variable is defined in terms of cross-sectional area reduction while the second scalar damage variable is defined in terms of the reduction (i.e., degradation) in the elastic modulus or elastic stiffness.