Strain-concentration factor of plane-strain notched rectangular bars under pure bending

Abstract

A new strain-concentration factor (SNCF) has been defined for plane-strain notched rectangular bars under pure bending. The nominal strain for this new SNCF is obtained from an assumed linear distribution of the longitudinal strain on the net section. This nominal strain is defined under the triaxial stress state at the net section. The new SNCF provides reasonable values for the non-linear distributions of the longitudinal strain, while the conventional SNCF provides unreasonable values. The new SNCF increases from its elastic value to a peak value with plastic deformation. On further deformation it gradually decreases and then increases up to the value at the general yielding. The relation between the new SNCF and M/M_Y, the ratio of the applied bending moment to the bending moment at yielding at the notch root, is independent of the stress- strain curve up to general yielding.