The plane elastostatic boundary value problem with V-notched singularity is formulated by a contour integral method for determining numerically the stress intensity factors. The integral formula is based on Somigliana type of reciprocal work in terms of displacement and traction vectors on the plate boundany. The characteristic singular solutions can be obtained on the basis of traction free boundary conditions of two radial edges. Two numerical example problems are treated in detail; the symmetric mode I type of notched plate with various interior angle, and the mixed mode type of cantilever subjected to end shear. The effect of domain divisions and integration contour on the numerical value of stress intensity factors is considered.
