...James C. Newman,, Jr.; Justin W. Shaw; Balkrishna S. Annigeri; Brett M. Ziegler The dashed curve is the calculated results using the upper-bound ΔK eff -rate curve, which fit the CA portion quite well. But the FASTRAN crack-closure model predicted that the crack would become dormant after...

... decreased Hertzian contact stresses. A correlation of backside cracking velocity versus target size was made based on a simplified elastic foundation analysis. 22 06 2011 23 06 2011 05 03 2012 05 03 2012 ceramics cracks fracture gas turbines silicon compounds steel...

...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...

... of these blades. HPT blades made of the nickel-based superalloy Mar-M002 have been found to suffer from stress assisted grain boundary oxidation (SAGBO) cracking. HPT blades removed from an RB211-24C aeroderivative industrial GTE were sectioned, and the cracks and microstructure were studied using scanning...

...Ian de Curieres; Marie-Christine Meunier; Pierre Joly The aim of the paper is to introduce methods to estimate the residual life of steam generators with alloy 600 thermally treated (TT) tubing, taking into account primary water stress corrosion cracking (PWSCC) as the main contributor damage...

... 27 05 2010 27 05 2010 cracks engines ignition time series When collecting the data for a stationary engine condition (all inputs held constant), the engine is first warmed up so that both the oil and coolant temperature remain constant. The goal of this work...

...Warren Miglietti; Madeleine Du Toit Both aviation and land based turbine components such as vanes/nozzles, combustion chambers, liners, and transition pieces often degrade and crack in service. Rather than replacing with new components, innovative repairs can help reduce overhaul and maintenance...

...Britta Laux; Sebastian Piegert; Joachim Rösler High-temperature diffusion brazing is a very important technology for filling cracks in components from single-crystalline nickel-base superalloys as used in aircraft engines and stationary gas turbines: Alloys, which are similar to the base material...

...Igor Simonovski; Leon Cizelj The dominant processes in the initialization and propagation of microstructurally short cracks include microstructural features such as crystallographic orientations of grains, grain boundaries, inclusions, voids, material phases, etc. The influence...

... the degradation of the TBC and determine the extent of TGO cracking, TGO growth, bond coat oxidation, and TBC failure location after long term exposure for up to 18,000 h . Optical microscopy and a scanning electron microscope (SEM) attached with an energy dispersive spectroscopy (EDS) system were used to study...

...Sung R. Choi; Robert W. Kowalik Interlaminar crack growth resistances were evaluated for five different SiC fiber-reinforced ceramic matrix composites (CMCs) including three gas-turbine grade melt-infiltrated Si C ∕ Si C composites. Modes I and II crack growth resistances, G I and G II , were...

... and the results were compared to field experience data. The absolute number of cycles to crack initiation appeared hard to predict, but the location and direction of cracking could be correlated well with field data. 05 01 2006 28 06 2006 gas turbines jet engines computational fluid dynamics...

...S. C. Forth; B. S. Annigeri; W. D. Keat The surface integral method, an indirect boundary element method that represents a crack as a distribution of force dipoles, has been developed to model three-dimensional nonplanar crack growth in complex structures. The finite body was effectively modeled...

... cracks with multiple origins at the core leading edge radius and extending down the airfoil span along the core surface. The longer cracks transitioned from stage II fatigue to crystallographic stage I fatigue propagation, on octahedral planes. An investigation of crack depths on the population of blades...

... treatments are to prevent crack initiation, to retard propagation of small cracks, and even to resist corrosion and wear damage. In this paper the literature on these technologies and their effects on component reliability and durability is reviewed, with an emphasis on shot peening (SP), laser shock peening...

...R. L. McAlpin; P. L. Talley; H. L. Bernstein; R. E. Holm The common failure modes of variable inlet guide vanes (VIGVs or IGVs) on industrial gas turbines are reviewed. These mechanisms include corrosion, cracking, and wear of the IGVs, their bushings and thrust washers. A new mechanism for IGV...

...Y. C. Zhou; T. Hashida Delamination cracking in thermal barrier coating (TBC) system is studied with the newly developed theoretical model. A semi-infinite long interface crack is pre-existing. The thermal stress and temperature gradient in TBC system are designated by a membrane stress P...

... for predicting the effects of time and temperature on CMC tensile rupture under various composite and engine conditions. These models are based on the average rupture behavior measured in air for oxide and SiC-based fibers of current technical interest. For example, assuming a cracked matrix and Larson-Miller...

... cracking susceptibility has been studied to obtain optimum condition for crack-free welds. Variations in cracking susceptibility as a function of welding heat input is discussed with reference to metallurgical characteristics of the welds. [S0742-4795(00)02003-2] Laser cladding of the IN738 alloy using...