engleski

A novel approach to the estimation of strain life fatigue parameters

Most of the existing methods for the estimation of strain life parameters were developed by correlating experimentally determined strain life parameters, directly and independently of each other, with one or more readily obtainable monotonic tensile material properties. In some cases, this resulted in relatively complicated expressions for the calculation of fatigue parameters, while in others, because of the poor correlation between certain fatigue and monotonic properties, constant values were assigned to some of these fatigue parameters. Since in the strain life approach the fatigue life of the material is defined by relationship, it is suggested that the estimation of the strain life fatigue parameters should be based on the analysis and connection of actual strain life data to an appropriate monotonic property. For the purpose of an initial verification of the proposed approach, estimation of fatigue parameters , b, and c was performed using data gathered for normalized and quenched and tempered high-strength low-alloy steels AISI 4140 and AISI 4142. Brinell hardness HB was chosen as a required monotonic parameter. Numbers of load reversals 2Nf calculated using experimentally determined and estimated fatigue parameters were analyzed and compared. They were found to be in very good agreement, thus confirming good predictive capabilities as well as general validity of the proposed approach to the estimation of strain life fatigue parameters.

Strain life; Fatigue parameters; Fatigue life estimation; Monotonic tensile properties

nije evidentirano