Abstract: The thermal weight function (TWF) method is extended to the universal weight function (UWF) method suitable for mechanical and thermal loadings. The UWF is dependent only on the crack configuration and body geometry, and is in-dependent of time and loads. The finite element implementation of the UWF method for 3-D Mode I cracks subjected to me-chanical and thermal loadings is given by using the multiple virtual crack extension (MVCE) method. The UWF method is especially suitable for determining the variation of transient stress intensity factors (SIFs) of a cracked body subjected to thermal and mechanical shock. Numerical results show that UWF method is of high efficiency and of good accuracy as the COD method.

Key words: Finite element method, Multiple virtual crack extension method, Stress intensity factor, Universal weight function method