COMPARISON OF METHODS FOR ESTIMATING NOTCH STRESS INTENSITIES AT SHARP V-NOTCHES

A number of finite element (FE) postprocessing methods have been developed for the computation of notch stress intensity factors (NSIFs). Factors such as varied formulations, field variables sampled, location/areas of the sampling points and the number of sampling points are known to affect the accuracy of the computed values of the NSIFs. The use of conventional finite elements at the notch tip in all of these methods also greatly affects the accuracy.The present work surveys the available FE based NSIF extraction methods and compares their efficacy in terms of accuracy of the computed NSIFs. Seven methods, variously based on stress, displacement, and energy, are considered. Our results indicate that displacement-based methods consistently provide the most accurate NSIFs relative to the number of sampling points.