... environment. Along with the final specimen geometry, the stress intensity equation and crack length monitoring equation are discussed. The stress intensity equation was converted to a standard polynomial equation in order to use a conventional automated fatigue crack growth rate software package. Symmetry...

... Fatigue crack growth testing of Inconel and multiphase 159 bolts is presented. The direct-current potential difference technique is shown to be successful in obtaining crack length data from the test bolts with short grip lengths. Three stress intensity solutions for round sections are presented...

... Stress intensity ( K ) predictions are presented using crack opening displacements with¼ points elements at the crack tip to simulate the crack tip singularity. These results are compared to available literature values under remote applied tension for a 2D thru-crack and a 3D semi-elliptical...

... are attributed to overload and underload effects from the LCF precracking. high cycle fatigue threshold stress intensity overloads loading history small cracks Ti-6Al-4V fracture mechanics Monty A. Moshier, 1 Theodore Nicholas, 1 and Ben M. Hillberry2 The Effect of Low Cycle Fatigue Cracks...

.... The fracture toughness at the onset of ductile crack extension is measured in terms of the J integral and converted to an equivalent stress intensity K J value using the standard relationship. The fracture toughness at this crack initiation point can then be compared with the K Q obtained using...

... A numerical method for predicting closure and its effects on thermomechanical crack growth has been developed. A finite element model, using linear-elastic fracture mechanics shape functions, is employed to predict crack tip displacements. The effective changes in stress intensity, and therefore...

.... The crack initiation and growth data are correlated with the water chemistry of the test. Low Alloy Steel fatigue high temperature water pitting crack initiation crack growth stress intensity ASME section III code ASME section XI code Harvey D. Solomont, gon E. DeLairt and Andy D. Unruh2...

... of the connections between the layers, load is transferred to the uncracked layer as the crack grows. This reduces the stress intensity and slows the crack growth rate. The model is used to analyze tests performed on a section of a wing spanwise lap joint. The crack was initiated at a rivet and grown under constant...

... debonding butt joint fracture stress intensity fracture toughness bimaterial crack bimaterial wedge finite element analysis Dan Zenkert ~ Effect of Manufacture-Induced Flaws on the Strength of Foam Core Sandwich Beams REFERENCE: Zenkert D., "Effect of Manufacture-Induced Flaws on the Strength...

... Cracks in SM50A steel for welding structure, chilled to 233 and 193K, were loaded by various stress intensity pulses with durations of 20, 40, and 80 μs to generate experimental data of critical stress intensity levels for crack instability. Fracture surfaces were observed by a scanning electron...

... surfaces. These examinations involved analysis of scanning electron and optical microscope images which enabled the maximum stress intensity factors to be calculated for each stage of crack growth. This paper describes the fractography methods and possible applications for a HSC model. image analysis...

... stress-intensity range (Δ K th ). The effect of load ratio on Δ K th in the air environment was, however, much more significant than that in wet hydrogen and dry environments (dry hydrogen and dry helium). At low load ratios (≲ 0.5), the values of Δ K th in the air environment were larger than those...

... zone size crack opening displacement J-integral stress intensity stainless steels crack closure stress ratio ]E0647 E0739 Michael W. Brown,^ Eduardo R. de los Rios,^ and Keith J. Miller^ A Critical Comparison of Proposed Parameters for High-Strain Fatigue Crack Growth REFERENCE: Brown, M. W...

... of determining plastic zone size are compared, and a crack growth correlation with crack-tip plasticity is proposed for remote loads not greater than the yield stress. biaxial stresses crack propagation fatigue (materials) plastic deformation stress intensity stainless steels Michael W. Brown...

... that such a nonstraight crack follows along the direction where Δ K II = 0 and the Δ K I - da/dN relations coincide with those for a straight crack under single K I mode. biaxial loading fatigue crack propagation fracture mechanics structural steel mixed modes stress intensity stress ratio branched...

... on the Mode I and Mode II crack-tip stress-intensity factors and also the T -stress. A secondary but important factor is the fracture ductility of the material around the crack tip, which itself is a function of biaxial stress state. biaxial stresses crack propagation crack initiation fatigue...

... We developed a computer-assisted data collection technique for flatjackloaded, short-rod specimens to readily obtain crack velocity V as a function of stress intensity factor K I . The technique facilitates the study of stress corrosion in glass and ceramic materials and allows us...

... -curve, (3) monotonic bulk prestraining lowers the R -curve whereas cyclic bulk prestraining raises it, and (4) the R -curve may be lowered by decreasing the monotonic loading rate. fracture toughness J R -curves load history prestrain cycles loading 4340 steel stress intensity /. D...

... this analysis, it is concluded that this safety margin is considerable. Depending upon the conditions considered to be realistic in practice, the margin could be upwards of 10 or more orders of magnitude. probabilistic fracture mechanics conservatisms test simulation safety factor stress intensity...

... stress fatigue part-through crack crack-opening displacement stress intensity titanium J. E. Hack} and G.R. Leverant^ Influence of Conripressive Residual Stress on the Crack-Opening Behavior of Part-Through Fatigue Cracks REFERENCE: Hack, J. E. and Leverant, G. R., "Influence of Compressive...