STRESS INTENSITY FACTORS AND CRACK PATHS FOR CRACKS IN PHOTOELASTIC MOTOR GRAIN MODELS

摘要

Computational analysis and two dimensional tensile tests on single motor grain fins suggest that cracks in fin tips are most likely to originate at the coalescence of the fin end tip radius with a small radius emanating from the side of the fin. Prior studies have indicated that under internal pressure, cracks on the fin axis are subject to similar stress peaks and may grow more readily than the former types due to an absence of shear modes. The present study focuses upon two types of cracks emanating from the former location called "off-axis" cracks and attempts to differentiate from the two types by their paths and SIF values, determined by the frozen stress photoelastic method.