A Strength Evaluation Method of a Sharply Notched Structure by a New Parameter, "The Equivalent Stress Intensity Factor"

Abstract

A new method is proposed to evaluate the strength of a sharply notched structure with a large notch angle. A new parameter, K_e which is to be called the equivalent stress intensity factor and which prescribes the singularity of stress distribution near the notch tip, is defined to evaluate the effect of a sharp notch on the fatigue and static strength. This method makes it possible to predict the strength of a notched structure by using the well-known parameters ΔK_th and K_Ic. Fatigue tests of HT60 (600 MPa-class high-strength steel) and SS41 (400 MPa-class mild steel) and a brittle fracture test of an acrylic plate were conducted, and the applicability of the parameter was verified.