抄録
The local strain approach is a very useful method to evaluate fatigue strength of complicated welded structures. In the local strain approach, the accuracy of measured local strain is very cirtical. The effects of the radius of toe grinding and the strain gage length on the accuracy of measured local strain and Δσ(= E·Δε) - Nc curves were examined in this study. An accuracy of 90% could be obtained for the measured local strain when the length of the strain gage was less than half the toe radius. For the measured local strain, a Δσ(= E·Δε) - Nc curves for welded structures agreed with that of the small round specimen. However toe grinding caused a decrease in the local strain, and as a result, Δσ decreased with a derease in strain concentration factor. The Δσ(= E·Δε) - Nc curves modified with toe grinding radius were proposed, and the results agreed with the test data for welded structures.
