Quantification of crack tip constraint effect based on the critical distance

Abstract The effect of crack tip constraint on the fracture properties of flawed components is a critical consideration in the safety assessment of engineering structures. In this work, an approximate expression of three‐dimensional von Mises stress fields ahead of the crack tip has been derived by referring to the classic Hutchinson‐Rice‐Rosengren (HRR) solution. The critical distance r c is chosen as the constraint parameter to quantify the level of the crack tip constraint. A theoretical relationship between the parameter r c and fracture toughness J Q has been proposed. The critical constraint parameter r c can be experimentally determined by using the critical fracture toughness J Q . The experimental results of compact tension (CT) and single edge‐notched bending (SENB) specimens with different crack tip constraint levels for SA‐508 and Q345B steels successfully validate the relationship between the critical fracture toughness J Q and the constraint parameter r c . According to the test results, the critical distance r c is feasible to quantify the crack tip constraint of CT and SENB specimens with different crack tip constraint levels.