Three-dimensional sharp V-notch stress intensity factor and strain energy rate density under creeping conditions

Abstract

Fracture evaluation of three dimensional (3D) notches in creeping solids have drawn considerable attention due to their potential application in structural integrity assessment. In this paper, the notch stress intensity factor (NSIF) and the strain energy rate density (SERD) rule are extended to 3D sharp V-notch tip under creeping conditions. In particular, the out-of-plane factor Tz is introduced to describe the 3D NSIF of creeping sharp V-notch tip field. The out-of-plane effect on the SERD is also studied based on the KN(t)-Tz solution. A method to evaluate the 3D sharp V-notch NSIF was proposed based on the concept of SERD. The link between the NISF and SERD of 3D sharp V-notch is established and discussed. It is found that the SERD is obviously influenced by the out-of-plane factor. The variations of NSIF along the thickness direction of 3D sharp V-notch front and the effect of creep time are also discussed. The accuracy of the presented evaluation form is also validated. The solution given in this paper could provide a new perspective and theoretical foundation on understanding the NSIF and SERD for sharp V-notch.