...Leila Ladani; Steven Nelson Mechanical fatigue crack nucleation and propagation is modeled in bimodal grain size aluminum alloy. A multiscale modeling approach in conjunction with a continuum based damage modeling technique, successive initiation, is used to determine microstructural site of crack...

... 2009 crack detection crack-edge stress field analysis crystal microstructure dislocation pile-ups fatigue cracks finite element analysis forging nucleation plastic deformation plasticity slip titanium alloys ultrasonic materials testing Ti-6242 crack initiation dwell fatigue...

... nucleation and propagation through random-clustered second phase particle fields. The proposed approach is capable of capturing the three-dimensional character of damage phenomena and the three stages of ductile fracture, namely, void nucleation, growth, and coalescence, at the level of discrete particles...

...Rajesh Prasannavenkatesan; David L. McDowell; Gregory B. Olson; Herng-Jeng Jou Nucleation of fatigue cracks at nonmetallic primary inclusions in high cycle fatigue of martensitic steel is computationally investigated. We explore the capabilities of an elastic interphase material adhered...

... the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally...

... elastic strain energy density is also examined. The effects of applying stress bound constraints on the SPF inversion are discussed, as are extensions of QSA to examine defect nucleation and propagation. Dawson , P. R. , Miller , M. P. , Han , T. S. , and Bernier , J. V. , 2005...

... in superplastic materials. Thanks to this technique, damage development during superplastic deformation of Al and Mg alloys is investigated and the three main steps of damage development (nucleation, growth, and coalescence) are discussed. 26 07 2007 24 01 2008 13 03 2008 aluminium alloys...

...D. Kumar; T. R. Bieler; P. Eisenlohr; D. E. Mason; M. A. Crimp; F. Roters; D. Raabe Simkin et al. (2003, “A Factor to Predict Microcrack Nucleation at Gamma-Gamma Grain Boundaries in TiAl,” Scr. Mater., 49(2), 149–154) proposed a relationship for predicting crack initiation in γ - Ti Al...

... to the tensile loading axis. The detailed strain distribution across the deformation bands showed a bell-like instead of steplike shape, indicating that the formation of these deformation bands was controlled by a local nucleation and growth process at a cross section in the polycrystalline sheet. Hundreds...

...Yanyao Jiang; Fei Ding; Miaolin Feng Fatigue process is described as the nucleation and growth of cracks to final failure. These two stages are generally modeled with completely different methods with no quantitative relationships between them. A number of fitting parameters are needed to consider...

... are developed near grain boundaries, and conversely smaller gradients at high temperatures (i.e., low Z values). The frequency of thermally activated grain boundary motion coupled with various levels of local orientation gradients lead to the operation of different mechanisms of DRX nucleation. At warm...

...Y. Liang; P. Sofronis Experimental evidence indicates that nickel-base alloys fail in the presence of hydrogen by ductile intergranular fracture. The degradation mechanism involves void nucleation at grain boundary carbides and grain boundary decohesion. In this study, a micromechanical model...

... a good correlation with the Zener-Hollomon parameter. In case of ELI grade, a mechanism of large grained superplasticity involving sliding of prior colony boundaries has been identified. However, deformation close to the transus in ELI grade causes nucleation of voids which may grow during soaking...

... becomes larger. It was also found that, when the composite is undergoing a relatively large plastic deformation (strain), the maximum interfacial normal stress is approximately linearly dependent upon the von Mises stress and the hydrostatic stress. Based on the stress criterion for void nucleation...