The Effect of Notch Depth and Notch Root Radius on the Averaged Strain Energy Density and on Fracture Load in U Notches under Bending

In this paper, the mean value of strain energy density criterion has been used to predict the critical fracture load in specimens with U-shaped notch under bending loads. An equation for calculation of averaged strain energy density in this zone has been presented. Bending loads under mode I have been considered. Two cases have been studied: 1) the control volume only includes the semicircular arc of the notch root, and 2) the control volume includes rectilinear edge of the notch. The effect of notch root radius and notch depth on the mean value of strain energy density has been studied in two cases above and the critical fracture load rate has been predicted. Finite Element Analysis has been carried out for verification. The studies show that the critical fracture load increases and then decreases by increasing the notch root radius. Also, this parameter decreases exponentially by increasing the notch depth.