Plastic Strain Distributions at the Net Section of Circumferentially Notched Cylindrical Bars.

Plastic strain distributions obtained from the hardness number distribution at the net section have been compared with those calculated using the finite element method. Notched bars with a U-shaped circumferential notch were made of austenitic stainless steel (SUS), Ni-Cr-Mo steel (SNCM)and low-carbon steel (S20C). In the deformation range up to the maximum tensile load Pmax, the strain distribution obtained using the two methods agreed well for all notch radii and materials employed. In the deformation range beyond Pmax of netched bars of SUS, the two strain distributions agreed well for high notch sharpness, while for low notch sharpness, the difference between the two strain distributions increased with increasing deformation and with initial notch radius. For SNCM, the two strain distributions agreed well beyond Pmax. Approximately the same strain distribution was produced prior to Pmax, in spite of the distinct difference in mechanical properties and notch strength ratio.