Stress Concentration and Fatigue Strength of Notched Specimens under Repeated Bending Moment (7th Report) : Circular Cylinder with a Diametral Hole (No. 4)

This report (continued from the 4th reoprt) is a investigation of fatigue strength of thin steel cylinders with one hole in the center ad shown in Fig.1-the shapes of the hole are rectangle (with circular corners) and circle (having diameter equal to the short side length of the rectangle). These specimens are large type of 104mm diameter and 2 mm thickness and tested by 500kg・m rotating bending machine. The results are summarized as following : (1) As the failure occurs at the point of maximum stress concentration on the periphery of the hole, the fatigue strength will depend upon the stress concentratoin factor of each cylinder, and then the equivalent values of form factors are calculated and measured by strain gage method. (2) The notch factors are roughly proportional to the form factors.