Effect of notch depth on strain-concentration factor of rectangular bars with a single-edge notch under pure bending

The FEM is employed to study the effect of notch depth on a new strain-concentration factor (SNCF) for rectangular bars with a single-edge notch under pure bending. The new SNCF Knew e is defined under the triaxial stress state at the net section. The elastic SNCF increases as the net-to-gross thickness ratio h0/H0 increases and reaches a maximum at h0/H0 = 0.8. Beyond this value of h0/H0 it rapidly decreases to the unity with h0/H0. Three notch depths were selected to discuss the effect of notch depth on the elastic–plastic SNCF; they are the extremely deep notch (h0/H0 = 0.20), the deep notch (h0/H0 = 0.60) and the shallow notch (h0/H0 = 0.95). The new SNCF increases from its elastic value to the maximum as plastic deformation develops from the notch root. The maximum Knew e of the shallow notch is considerably greater than that of the deep notch. The elastic Knew e of the shallow notch is however less than that of the deep notch. Plastic deformation therefore has a strong effect on the increase in Knew e of the shallow notch. The variation in Knew e with M/MY, the ratio of bending moment to that at yielding at the notch root, is slightly dependent up to the maximum Knew e for the shallow notch. This dependence is remarkable beyond the maximum Knew e . On the other hand, the variation in Knew e with M/MY is independent of the stress–strain curve for the deep and extremely deep notches.