Engineering topics
Publications and source records attributed to Orange, T. W..
Recommendations are given for the design, preparation, and static fracture testing of surface crack specimens. The recommendations are preceded by background information including discussions of stress intensity factors, crack opening displacements, and fracture toughness values associated with surface crack specimens. Cyclic load and sustained load tests are discussed briefly.
The purpose of this paper is to show the effects of experimental imprecision on the stress intensity factors calculated for various practical specimen types. A general form equation for the stress intensity factor is presented, and a general error equation is derived. The expected error in the stress intensity factor is given in terms of the precision levels of the basic experimental measurements and derivatives of the stress intensity calibration factor. Nine common fracture specimen types are considered, and the sensitivity of the various types to experimental error is illustrated. Some implications for fracture toughness testing and crack growth rate testing are discussed, and methods of analysis are proposed to compensate for the effects of experimental error.
Effects of experimental imprecision on the stress intensity factors calculated for various practical specimen types are shown. A general form equation for the stress intensity factor is presented and a general error equation is derived. The expected error in the stress intensity factor is given in terms of the precision levels of the basic experimental measurements and derivatives of the stress intensity calibration factor. Nine common fracture specimen types are considered, and the sensitivity of the various types to experimental error is illustrated. Some implications for fracture toughness testing and crack growth rate testing are discussed and methods of analysis are proposed to compensate for the effects of experimental error.
A simple stress intensity factor expression is given for a deep edge crack in a plate in tension. The shapes of cracks opened by tension or bending are approximated by conic sections, and the conic section coefficients are related to plate geometry by very simple empirical equations. The magnitude of the crack displacement is a function of applied load, plate geometry, and the elastic constants of the plate material. The shape of a loaded crack in a semiinfinite plate is, approximately, a portion of an ellipse whose semimajor axis is about three times the crack length. As the crack length (relative to the plate width) increases, the crack shape becomes parabolic, then hyperbolic, the acuity of the hyperbola increasing with the relative crack length.
Crack shapes and stress intensity factors for deep edge crack in plate under tension or bending
Semiempirical modification of Irwin fracture analysis for semielliptical surface crack in metal plate
Fracture mechanics theory used to determine effects of crack dimensions and material properties on fracture stresses for thin metal sections with through and part-through cracks
Stress intensity factor and shape of edge crack in plate under tension
Ti-Al-Sn and Al alloys thin sectioned specimens cryogenic fracture strength, discussing surface crack fracture behavior
Determination of stresses for surface cracks in metal sheets and plates
Metal surface through and part through cracks, investigating dimensions and material properties effects on fracture stresses
Fracture tests of thin metal sections containing through and part-through cracks
Semiempirical fracture analysis for semielliptical surface crack in plate
Multiple element continuity gage measures plane stress crack growth plus surface crack growth under plane strain conditions. The gage measures flat and curved surfaces and operates at cryogenic temperatures.
Effect of aluminum alloy test specimen size on fracture toughness at high stress ratios
Crack propagation measurement by foil strain gauge on flat and curved surfaces at cryogenic temperatures
Continuity gauge measurement of crack growth on flat and curved surfaces at cryogenic temperatures
Low temperature notch toughness of cryoformed pressure vessels using 301-type stainless steel modifications