A fractographic study of crack propagation under creep-fatigue conditions.

Modelling of fatigue crack propagation in Inconel 718 under hold time conditions

In this thesis an investigation and modelling of the fatigue crack propagation in the nickel based superalloy Inconel 718, with a special emphasis on the effect of hold times, is presented. The modelling work has been concentrated on describing the hold time fatigue crack propagation by using the concept of a damaged zone in front of the crack tip, which is believed to have a lowered resistance...

The Fracture Mechanics Concept of Creep and Creep/Fatigue Crack Growth in Life Assessment

There is an increasing need to assess the service life of components containing defect which operate at high temperature. This paper describes the current fracture mechanics concepts that are employed to predict cracking of engineering materials at high temperatures under static and cyclic loading. The relationship between these concepts and those of high temperature life assessment methods is ...

Stochastic modeling of fatigue crack propagation

This paper presents a stochastic model of fatigue-induced crack propagation in metallic materials. The crack growth rate predicted by the model is guaranteed to be non-negative. The model structure is built upon the underlying principle of Karhunen±Lo eve expansion and does not require solutions of stochastic di€erential equations in either Wiener integral or Itô integral setting. As such this ...

Fatigue crack propagation in microcapsule - toughened epoxy

The addition of liquid-filled urea-formaldehyde (UF) microcapsules to an epoxy matrix leads to significant reduction in fatigue crack growth rate and corresponding increase in fatigue life. Mode-I fatigue crack propagation is measured using a tapered doublecantilever beam (TDCB) specimen for a range of microcapsule concentrations and sizes: 0, 5, 10, and 20% by weight and 50, 180, and 460 lm di...

High Temperature Fatigue Crack Propagation in INCONEL718