TWI Industrial Member Report Summary 59/1978
By T R Gurney
In the light of findings reported by other investigators an examination has been made of the correlation which exists between the parameters C and m in the da crack propagation equation - da/dN = C(DeltaK)m. This study has taken into account a dN wide range of results but has been restricted to steels tested in air under essentially pulsating tension (R = 0) loading. It has been confirmed that m and Log C are linearly related. The significance of this finding with regard to choice of material and its influence on the fatigue life of welded joints has been examined.