A special notched tensile specimen to determine the flow stress-strain curve of hardening materials without applying the Bridgman correction

Study of low‐temperature effect on the fracture locus of a 420‐MPa structural steel with the edge tracing method

“…In this study, the specimen deformation is characterized by the average true strain ε, which is defined by the minimum cross-section area reduction 39 :…”

“…The true stress-strain curves in Figure 9B cannot be used directly for numerical analyses, due to the triaxial stress state in the specimen necked region after diffuse necking. 21,37,39,45 Bridgman 21 proposed an analytical correction method based on axisymmetric analysis of a necked round bar specimen (Equation 6). However, the Bridgman correction is difficult to practice because the current notch curvature radius should be measured.…”

A method for determining material's equivalent stress-strain curve with any axisymmetric notched tensile specimens without Bridgman correction

“…It indicates that, with a single correction parameter, the true stress output from an axisymmetric notched tensile specimen with 00 1.5 aR  or 00 2 aR  can be converted to the material's equivalent stress. This has been investigated by the authors for hardening materials [21], and the axisymmetric notched tensile specimen with 00 2 aR  has been proved to present a good agreement between the material's equivalent stress-strain curve and the corrected stress-strain curve with a single G factor.…”

“…An alternative method with more accurate results and lower test cost has been proposed recently to measure material's flow stress-strain curve [21]. The authors further studied the axisymmetric notched tensile specimen with numerical analyses and a special notch geometry with 00 2 aR  has been identified.…”

“…Recent study by the authors [21] showed that the true stress calculated by Eq. (2) with the axisymmetric notched tensile specimen is independent of the specimen outer diameter 0 d when the geometry condition 0 0…”