Within the concept of physical mesomechanics of materials the peculiarities of fatigue crack propagation in specimens of 25Cr1Mo1V steel with lateral notches were investigated under zero-to-tension stress cycles. The use of the television-optical strain measurement method at the mesolevel allowed a comprehensive description of the fatigue crack tip opening behaviour. For this purpose, the shear strain intensity parameter (SSI - γavg, γavg 1), calculated for fatigue cracks of various lengths, was used. It is established that within the FCGR range (fatigue crack growth rate) of 10-4÷3·10-3 mm/cycle the dependences "lg da/dN - lg γavg (lg γavg 1)" are well approximated by the linear function. Moreover, the SSI values increase with an increase in the crack length, which, on the whole, agrees satisfactorily with the results of fractographic research. The main regularities in the fatigue crack growth during the localization of plastic deformations at its tip are revealed and described numerically.
|Журнал||International Journal of Terraspace Science and Engineering|
|Состояние||Опубликовано - 2010|
ASJC Scopus subject areas