Abstract
The effect of a free surface on fatigue crack behaviour is discussed in the paper and generalized stress intensity factor methodology is used for a reliable estimation of the fatigue crack propagation rate in the area close to a free surface, where the effect of vertex singularity is important. It is shown that a decrease in the stress singularity exponent close to the vertex point leads to a decrease in the fatigue crack propagation rate and contributes to a typical curved crack front shape. The numerical estimations of the crack shape correspond well with experimental observations taken from the literature. Further change of the stress singularity exponent for thin structures was studied on M(T) specimens with different thicknesses. The proposed methodology facilitates explanation of the experimentally observed decrease in the fatigue crack propagation rate (FCPR) for thin structures. It is shown, that decrease of FCPR depends on Poisson’s ratio and parameters of the Paris–Erdogan law for corresponding materials. These results can at least partially explain the effect of a free surface on fatigue crack behaviour and help towards a more reliable estimation of the residual fatigue lifetime of the structures considered.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
