Fracture and Fatigue-Crack-Propagation Characteristics of 1/4-Inch Mill-Annealed Ti-6Al-4V Titanium Alloy Plate

摘要

The fracture and fatigue-crack-propagation behavior of central through-the-thickness cracks has been evaluated in 1/4-inch-thick mill-annealed titanium alloy plate. The influence of crack aspect ratio on the fracture or residual strength of three panel widths has been determined. The fatigue-crack-propagation rates for various maximum stresses, stress ratios, and panel widths have been evaluated. It was observed that elastic fractures in the presence of central through-cracks do not occur in panels of this material less than 18 inches wide. Uniform and regular fatigue-crack-propagation behavior is noted. A fatigue-crack-propagation threshold is evident below 3 or 4 ksi/sq in. Power law modeling of rate data, crack life prediction, and interpretive discussions were also considered. (Author)