Statistical Estimation of <i>S-N</i> Curves for Structural Carbon Steels Using Their Static Mechanical Properties

Abstract

A statistical estimation method of S-N curve for structural carbon steels using their static mechanical properties was proposed. Firstly, S-N data series for pure iron and structural carbon steels were extracted from "Database on Fatigue Strength of Metallic Materials" published by the Society of Materials Science, Japan (JSMS) and S-N curve for each material was obtained by using the JSMS standard; "Standard Evaluation Method of Fatigue Reliability for Metallic Materials-Standard Regression Method of S-N Curve-". Secondly, correlations between regression parameters and static mechanical properties were investigated. As a result, the relationships between regression parameters and static mechanical properties (e.g. fatigue limit E and static tensile strength  B) have showed significant correlations. Based on these correlations, S-N curves for structural carbon steels were successfully predicted from their static mechanical properties. Moreover, using the distribution of fatigue limit E, the percentile points for the predicted S-N curve were also estimated. It was finally confirmed that 81% of S-N data series fall within the range of estimated interval between-3s and +3s, where s means a standard deviation.

Construction of Electronic Factual Database on Very High Cycle Fatigue Properties for Structural Metallic Materials

“…Book style of the same data compilation had been also published at the same time by the JSMS and Elsevier Science B. V. [3]. Based on this database, the above task-force committee in the JSMS has analyzed fatigue properies of metallic materials such as S-N curves and their statistical characteristics [4,5] by applying an useful analytical method standardized by the JSMS [6].…”