Calculating yield locus of sheet material using crystallite orientation distribution function

Abstract

The average texture over thickness was measured by the Schulz reflection method for determining one quadrant of pole figure of aluminum sheet 1100-H14. The texture measured is represented by a three-dimensional orientation distribution function. Yield locus and r-value are calculated using the theory developed by Bishop and Hill, in which an orientation distribution function is used as a volume fraction of certain orientated crystals. A chain of the measurement and calculations is executed by the micro- and large-computer 'quasi-on-line'. The calculated yield locus is close in shape to that measured by the biaxial compression test except a deviation based on Bauschinger effect. The calculated directional variations of stress in some strain or stress states and of r-value are in good agreement with observed ones.