On the Yielding of Twist Steel Bar

Abstract

The yielding of steel proceeds in successive appearance of flow layers. Having been taken account of it, the yielding phenomena of bending steel bar has been fully explained by the authors. In the present paper the yielding phenomena of twist steel bar is discussed as an another example of yielding of steel under uneven distribution of stress. In the first part are exhibited the results of measuring the stress existing in a yielding bar subjected to pure torsion. It leads to the conclusion that the twisted bar yields by the same mechanism as that of the yielding of bent steel beam. Then the problems of elasto-plastic torsion may generally be treated analytically in the same fashion as in the case of bending.