Understanding the fatigue crack growth phenomenon in railheads requires a study of driving forces such as the crack tip opening and sliding displacements, under repeated rolling contact. Finite element simulations, allowing elastic-plastic deformation, and mixed-mode crack growth laws were utilized to demonstrate that the fatigue crack growth rates display a minimum after a finite amount of cra...

This article presents a study of fatigue-crack propagation behavior in Nitinol, a 50Ni-50Ti (at. pct) superelastic/shape-memory alloy, with particular emphasis on the effect of the stress-induced martensitic transformation on crack-growth resistance. Specifically, fatigue-crack growth was characterized in stable austenite (at 120 8C), superelastic austenite (at 37 8C), and martensite (at 265 8C...

The multiscale nature of cracking in ferroelectric ceramics is explored in relation to the crack growth enhancement and retardation behavior when the direction of applied electric ®eld is reversed with reference to that of poling. An a priori knowledge of the prevailing fracture behavior is invoked for the energy dissipated in exchange of the macroand micro-crack surface. To avoid the formalism...

The optimal material processing in steel industry is difficult because of the multi-constituent and multiphase character of the commercial steels, variety of the possible processing paths, and plant specific equipment characteristics. This paper shows implementation of the genetic programming approach for crack presence modeling after rolling. The data (110 samples covering 7 different steel gr...

The present paper is concerned with the application of a “plasticity-induced” crack closure model to study fatigue crack growth under various load histories. The model was based on the Dugdale model but modified to leave plastically deformed material in the wake of the advancing crack. The model was used to correlate crack growth rates under constant-amplitude loading and then used to predict c...

In-phase TMF crack growth testing with different lengths of the hold time at the maximum temperature of 550C has been conducted on Inconel 718 specimens. Focus has been on establishing a method for TMF crack growth testing and investigating the effect of high temperature hold times on the TMF crack growth of the material. The tests are compared to isothermal crack propagation tests and show go...

Existence of cracks in industrial structures is one of the important causes of their failure, especially when they are subjected to important axial compressive forces that might lead to buckling. Therefore, it must be considered in stress analysis and designing and loading of such structures. In this paper, the buckling and post-buckling behaviors of stainless-steel cracked plates under axial c...

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...