Determination of histories of SIF distributions for axial semi-elliptical surface cracks in hollow cylinders subjected to thermal shock

The basic equations for a 3D thermal weight function method for Mode I are derived. A novel technique, referred to as the multiple virtual crack extension (MVCE) technique, is proposed for solving the basic equations. Specially selected linearly independent VCE modes can be used directly as shape functions for the interpolation of unknown stress intensity factors (SIFs). The coefficient matrix of the final system of equations is a triple-diagonal matrix and the values of the coefficients on the main diagonal are large. The system of equations has good numerical properties. Complex situations in which the SIFs vary dramatically along crack fronts can be well simulated by the MVCE technique. Hollow cylinders with various axial semi-elliptical surface cracks were solved. Examples show high efficiency and good accuracy.