...James C. Newman, Jr.; Balkrishna S. Annigeri Plasticity effects and crack-closure modeling of small fatigue cracks were used on a Ti-6Al-4V alloy to calculate fatigue lives under various constant-amplitude loading conditions (negative to positive stress ratios, R) on notched and un-notched...

...D. Gustafsson; J. J. Moverare; K. Simonsson; S. Sjöström Turbine disks are of large importance to turbine designers as they are exposed to hot environment and subjected to high loads. In order to analyze such components with respect to fatigue crack initiation, the work generally starts...

... casting failure (mechanical) fatigue cracks fatigue testing gas turbines nickel alloys polymer blends stress analysis stress-strain relations Ni base DS superalloy gas turbine blade biaxial fatigue high temperature life prediction About 40% of electricity generated by thermal...

... for each oxygen partial pressure and frequency values exhibit nearly linear responses with increasing Δ K values. When the oxygen partial pressure is increased, an increase in the fatigue crack growth rates is observed. This points to the oxygen interaction at the crack tip as being responsible...

... geometries. Crack nucleation scatter is estimated based on the variability associated with smooth specimen and fatigue crack growth data, including the influences of correlation among crack nucleation and growth phases. The influences of crack nucleation and growth variability on life and probability...

... by the fatigue crack growth phase and is strongly dependent on the magnitude of the stress values in the contact region. These stress values often have the most influence on small cracks where traditional long-crack fracture mechanics may not apply. A number of random variables can be used to model...

... of the turbine section. 14 12 2007 11 11 2008 09 04 2009 blades discs (structures) failure (mechanical) failure analysis fatigue cracks finite element analysis gas turbine power stations mechanical testing nozzles stress analysis surface cracks turbogenerators vibrations...

...Xijia Wu A nonlinear creep/dwell interaction model is derived based on nucleation and propagation of a surface fatigue crack and its coalescence with creep/dwell damages (cavities or wedge cracks) along its path inside the material, which results in the total damage accumulation rate as given by d...

...Irebert R. Delgado; Bruce M. Steinetz; Clare M. Rimnac; John J. Lewandowski The fatigue crack growth behavior of Grainex Mar-M 247 is evaluated for NASA’s turbine seal test facility. The facility is used to test air-to-air seals primarily for use in advanced jet engine applications. Because...

...Srikant Ranjan; Nagaraj K. Arakere A comprehensive fracture-mechanics-based life prediction methodology is presented for fcc single crystal components based on the computation of stress intensity factors (SIFs), and the modeling of the crystallographic fatigue crack growth (FCG) process under mixed...

... 11 01 2008 aluminium cast iron engines fatigue cracks fatigue testing life testing thermal stress cracking thermomechanical treatment Due to today’s demands to reduce cost and product time to market, engineering procedures are increasingly using more sophisticated simulation...

... with stress/strain concentrations and stress/strain gradients appear to be the most important sites for fatigue crack initiation. The paper addresses a nonlocal concept for cyclic life prediction of notched components. Contrary to various local approaches in the field, the proposed method explicitly accounts...

.... In contrast, the difference between the isotropic Hertzian contact (Eq. 13 ) with case A is significantly higher (within 10%). Weighted percentage difference in normal contact pressure for the orthotropic and isotropic spherical contact, as compared to case A The fatigue crack nucleation...

... that predict fatigue crack initiation life, fatigue crack growth life, fatigue limit, fatigue crack growth threshold, crack size at initiation, and fracture toughness. Using microstructure information as material input, the code is capable of predicting the average behavior and the confidence limits...

..., 2003; final revision, March 1, 2004. IGTI Review Chair: A. J. Strazisar. 13 June 2004 01 October 2003 01 March 2004 24 06 2005 jet engines materials testing aerospace test facilities aerospace safety life testing crack detection aerospace materials fatigue cracks...

..., 2003, Paper No. 2003-GT-38659. Manuscript received by IGTI, October 2002, final revision, March 2003. Associate Editor: H. R. Simmons. 16 June 2003 01 October 2002 01 March 2003 15 04 2005 rotors condition monitoring fatigue cracks vibration measurement crack...

... results in fatigue crack initiation along the “critical” octahedral planes. A “critical plane” fatigue modeling approach was developed in the present study to analyze high cycle fatigue (HCF) failures in single crystal materials. This approach accounted for the effects of crystal orientation...

...Y. Yamashita; M. Shinozaki; Y. Ueda; K. Sakano Fatigue crack growth prediction methods using three-dimensional finite element analyses were investigated to improve the predictability of part-through surface crack growth life. First, a direct analysis method of cyclic finite element analysis...

... from service of the serious-corrosive discs to assure the structural integrity of this aeroengine. 01 10 2003 01 03 2004 aerospace engines life testing gas turbines vibrations crack detection fatigue cracks corrosion fatigue blades The turbine blades of an aero-engine...

... by IGTI, Dec. 2000, final revision, Mar. 2001. Associate Editor: R. Natole. 04 June 2001 01 Dec 2000 01 Mar 2001 27 12 2002 fatigue creep fatigue cracks titanium alloys nickel alloys gas turbines stress effects high-temperature effects fracture mechanics design...