Fatigue crack propagation under tension-tension loading is observed in ( I trunsjormcition-tougheried purtiully stabilized zirconia (PSZ) certimic wnt~iining 9 mol% M g O . Such subcritical crack p m v t h behavior is clernonstrciterl to be licully induced, based on u comparison with behuvior unrler ,sirstciinerl loading (ut the maximum loud in thejiitigue cycle) and at varying c~clic~,fi-riluc...

A new approach was developed for the evaluation of energy release rate by the virtual crack closure technique in quadratic and linear elements. The generalized method allows arbitrary placement of the side nodes for quadratic elements and thus includes both standard elements, with mid-side nodes, and singularity elements, with quarter-point nodes, as special cases of one general equation. It al...

in this paper the critical strain energy release rate for t300/913 carbon-epoxy laminated composites has been studied using ansys finite element software based on virtual crack closure technique ( vcct ). compact tension ( ct ) specimen has been used for numerical analyses and the geometrical dimensions have been extracted from the existing references. the results obtained from the finite eleme...

Mechanical behaviors at fatigue crack tips of cracked specimens under negative loading ratios are studied in detail by the finite element method this paper. Three factors induced specimen type and on field discussed, including constraint, compressive effect (CL effect) contact closure. For mode I ratios, effects CL closure plastic strain accumulations dominant, with constraint being minor. The ...

Fatigue crack growth (FCG) rates have previously been reported in forged Ti6Al-4V aero-engine disk material under the conjoint action of LCF and HCF cycles at room temperature. It is found that systematic increases in LCF overload, applied prior to the commencement of the HCF cycles, reduce the contribution of the HCF cycles to crack growth rates. The application of overload also enhances the s...

(FBRs). The factors influencing fatigue lifetime in sodium compared with that in air were investigated by observation of surface cracks in 316FR steel. Furthermore, the effects of sodium environment on fatigue were investigated based on examining the results of thermal striping tests, etc., obtained up to now. The results of the fatigue tests show that many micro cracks in the shearing directio...

Recent developments in fracture mechanics analyses of the interfacial crack problem are reviewed. The intent of the review is to renew the awareness of the oscillatory singularity at the crack tip of a bimaterial interface and the problems that occur when calculating mode mixity using numerical methods such as the finite element method in conjunction with the virtual crack closure technique. Es...