On the Statistica1 Prediction on Fatigue Strength of Weld Toe in Transverse Strength Member of Ship Hull Construction

Abstract

In this report is studied the method predicting the fatigue crack initiation life, Nc, with probability of failure, P, in welded structure members of mild steel. As a result, it is shown that the P-ΔS-Nc curve in weld toe of structure members could be estimated using the P-Δε-Nc curve in mild steel and the expectation and variance of logarithm of elastic stress concentration factor, ln (K_t^^w), in weld toe. The propriety of the P-ΔS-Nc curve in the transverse strength members of ship hull construction is confirmed by the comparison with the results of fatigue test on the model of the various transverse strength members, and it is clarified that the ΔS-Nc curve at P=5% is available as the design curve for high cycle fatigue more than 10^4 cycles.