Calculation of mode III stress intensity factors by the weak-form quadrature element method

A weak-form quadrature element method is employed to calculate the mode III stress intensity factors based on the subregion generalized variational principle. A circular complementary energy region, where stresses are selected as variables, is divided at a crack tip, and a potential energy region, where displacements are chosen as variables, is adopted in the remote area. A system of algebraic equations is deduced eventually which can be solved for the stress intensity factors directly. The sensitivity of the involved parameters is discussed. High accuracy and high efficiency of the method are highlighted while solving several benchmark problems.