STRESS INTENSITY FACTORS AND WEIGHT FUNCTIONS FOR LONGITUDINAL SEMI-ELLIPTICAL SURFACE CRACKS INSIDE THICK-WALLED CYLINDERS USING HIGHLY-REFINED FINITE-ELEMENT MODELS

摘要

Fracture mechanics and fatigue crack-growth analysis rely heavily upon accurate values of stress intensity factors. They provide a convenient, single-parameter description to characterize the amplitude of the stress-field singularity at the crack tip, and are used to correlate brittle fracture and crack growth in pressure vessel and piping applications. Mode-l stress intensity factors that have been obtained for longitudinal semi-elliptical surface flaws on the inside of thick-walled cylinders using highly-refined finite element models are investigated. Using these results, weight function solutions are constructed and selected geometries are validated.