ABSTRACT

CHAPTER 13

MICRO-TO-MACRO TRANSITION

Some fundamental aspects of the transition in the constitutive description

of the material response from microlevel to macrolevel are discussed in this

chapter. The analysis is aimed toward the derivation of the constitutive

equations for polycrystalline aggregates based on the known constitutive

equations for elastoplastic single crystals. The theoretical framework for this

study was developed by Bishop and Hill (1951a,b), Hill (1963,1967,1972),

Mandel (1966), Bui (1970), Rice (1970,1971,1975), Hill and Rice (1973),

Havner (1973,1974), and others. The presentation in this chapter follows

the large deformation formulation of Hill (1984,1985). The representative

macroelement is dened, and the macroscopic measures of stress and strain,

and their rates, are introduced. The corresponding elastoplastic moduli

and pseudomoduli tensors, the macroscopic normality and the macroscopic

plastic potentials are then discussed.