Determination of Macro- and Microstresses in Deformed Materials by Application of the Strain Function Method

Abstract

The distribution of experimentally determined lattice spacings D versus sin 2 ψ (ψ the polar angel of the measurement direction) have often been shown to be typically non-linear in case of uniaxially strained or of rolled materials, even if the texture is weak. Plastic anisotropy is generally said to be the origin of this effect. During deformation the constraints between the crystals cause microstresses which are dependent on the orientation of the crystals with respect to the specimen system. The contribution of these orientation-dependent microstresses to the experimentally observed strains depend on the direction of measurement and on the lattice plane under study. In the present paper the recently developed method to determine the strain- and stress functions, i.e. the orientation dependencies of the strain- and stress-tensor components, from the lattice strain distributions of several lattice planes will be applied. The results enable one to determine both, macro- and microstresses. Examples will be given for uniaxially deformed and for rolled materials.