Experimental Determination of Side Boundary Effects on Stress Intensity Factors in Surface Flaws.

摘要

A technique consisting of stress-freezing photoelasticity coupled with a Taylor Series Expansion of the maximum local in-plane shearing stress known as the Taylor Series Correction Method (TSCM) is applied to the determination of stress intensity factors (SIF's) in flat bottomed surface flaws of flaw depth/length ratios of approximately 0.033. Flaw depth/thickness ratios of approximately 0.20and 0.40were studied as were plate width/crack length ratios of approximately 2.33and 1.25,the former of which corresponded to a nearly infinite width. Agreement to well within 10% was found with the Rice-Levy and Newman theories using a depth-modified secant correction and equivalent flaw depth/length ratios. The Shah-Kobayashi Theory,when compared on the same basis,was lower than the experimental results. On the basis of the experiments alone,it was found that the SIF was intensified by about 10% by decreasing the plate width/crack length from 2.33to 1.25. (Author)