A global collocation technique for the solution of opening mode crack problems

A review of various experimental and numerical techniques for determination of fracture mechanics calibration functions (i.e., the variation of K1 and CMOD with crack length) revealed that neither technique, employed independently, can determine K1, CMOD, and full field stresses in closed form over a wide range of crack lengths. To fill this void, a combined experimental/numerical collocation technique based on a series expansion of the modified Westergaard functions was developed. This technique uses both boundary conditions, known a priori, and interior stress field conditions, determined using a suitable experimental technique, for analysis of two dimensional, finite body, opening mode crack problems. This paper reports on an investigation of the accuracy of this technique and its sensitivity to errors in experimental data for a sample problem of practical interest.