GS0802 構造用鋼材における切欠引張強さ比の応力三軸度およびひずみ硬化指数依存性(GS08-01 構造部材・強度評価1,GS08 構造部材・強度評価)

Abstract

Dependence of notch strength ratio on stress triaxiality and strain hardening exponent was investigated for a variety of structural steels. Both the notched specimens with different notch acuities and the unnotched specimens were employed to obtain a wide range of stress triaxialitity. All specimens were loaded up to break under tensile loading. Notch strength ratio was defined by a ratio of notch tensile strength to tensile strength of the material. The notch tensile strength to break the notched specimen depends on the stress-state characterized by stress triaxiality. Notch strength ratio increased with increasing stress triaxiality, which eventually reached the limiting value in the range of high stress triaxiality. The limiting notch strength ratio was well correlated with strain hardening exponent, and could be used conveniently to estimate the upper limit load to break the mechanical component in failure analysis.