Application of approximate weight functions in fracture analyses of thermally stressed structures

Abstract

The approximate weight function method is applied to two types of crack problems involving thermal stresses. An analytical stress intensity factor expression (approximate) is derived for the case of a centre crack in a finite plate subjected to a quadratic thermal gradient. The analytical solution agrees very well with the finite element results in the literature. Another problem studied is that of internal axial crack(s) in a long cylinder with steady state thermal gradient across the wall thickness; results for this case are also satisfactory. The success of the approximate weight function method suggests that it may sometimes be preferred to the finite element method, which is extensively used today when treating crack problems of thermally stressed structures.