INFLUENCE OF THE BAUSCHINGER EFFECT ON THE SUBSEQUENT YIELD CONDITION.

Abstract

Plastic behavior of metal under complex loading is experimentally investigated by subjecting thin-walled tubular specimens of brass to combined axial load, internal (or external) pressure and torsion. The subsequent yield surfaces after some preloadings are established in the axial-circumferential-shear stress space. The yield surfaces which are dependent on the Bauschinger effect are obtained in all quadrants of the two principal stress-space by coaxial stress probes. The effect of the rotation of stress axes on the yield surface is studied by determining the yield stresses with rotating stress probes. Experimental results are represented in the deviatoric plane, and the influence of the Bauschinger effect and the rotation of stress axes on the subsequent yield surface are discussed. It is shown that, when the subsequent yield surfaces after radial preloadings are represented in the deviatoric plane, they are congruent with one another irrespective of the directions in preloading, if they have the same amount of prestrain.