Local flexibility of an elliptical cracked shaft under bending and tension

Compared with the widely used straight front crack model, an elliptical front crack has been found to be more accurate and realistic for modeling the transverse surface crack in rotating machinery. Therefore, based on the strain energy release rate (SERR) approach and the closed-form results of SIFs, the local flexibilities of an elliptical cracked shaft submitted to bending, axial tension and combination of both are derived and solved by means of numerical integration technique. Once the elliptical front and shape variation are considered, the obtained flexibility values are reduced obviously in contrast with the current results, especially for the deeper surface cracks.

► The elliptical front is more accurate and realistic for modeling the transverse surface crack.
► Several local flexibilities of an elliptical cracked shaft are derived using SERR approach.
► The flexibility values are lower than the current results, especially for the deeper crack.
► The results could be used for accurate cracked-rotor dynamic analysis.