It is generally accepted that the fatigue crack growth (FCG) depends mainly on the stress intensity factor range (DK) and the maximum stress intensity factor (Kmax). The two parameters are usually combined into one expression called often as the driving force and many various driving forces have been proposed up to date. The driving force can be successful as long as the stress intensity factor...

When in the presence of liquid metal environments, structural materials can potentially lose the ability to deform and plastically flow. In the case of a ductile material, the result of this reduction in flow ability is a transition from ductile to brittle behavior, resulting in a brittle-like failure. This phenomenon is known as liquid metal embrittlement (LME) and is a subset of the more comm...

Fatigue crack growth rate depends not only on the load amplitude, but also on the morphology of crack path. The strain energy density theory has the ability to analyze crack growth rate. A strain energy density crack growth model is proposed. It can predict the lifetime of fatigue crack growth for mixed mode cracks while an equation for mode I crack is also obtained. The validity of the model i...

ÐGamma-TiAl based alloys have recently received attention for potential elevated temperature applications in gas-turbine engines. However, although expected critical crack sizes for some targeted applications (e.g. gas-turbine engine blades) may be less than 0500 mm, most fatigue-crack growth studies to date have focused on the behavior of large (on the order of a few millimeters) through-thick...

This study presents a numerical approach for modelling the Corrosion Fatigue Crack Growth (CFCG) in conventional casting and additively manufactured Ti6Al4V alloys. The proposed model, based on Peridynamics (PD), combines PD (FCG) model diffusion order to couple mechanical fields existing material due impact of environmental fatigue. field is responsible characterisation changes structure fatig...

As a first step towards a new crack healing methodology for cyclic loading, this paper examines two promising crack-tip shielding mechanisms during fatigue of a microcapsule toughened epoxy. Artificial crack closure is achieved by injecting precatalyzed monomer into the crack plane to form a polymer wedge at the crack tip. The effect of wedge geometry is also considered, as dictated by crack lo...

The role of grain bridging in affecting the initial rising portion of the R-curve and the transient, non-steady-state behavior of short cracks during (cyclic) fatigue-crack propagation has been quantitatively examined in a 99.5% pure alumina. Fatigue-crack growth properties for both long and short ( af < 2 mm) cracks emanating from machined notches (root radius, 15–150 m) were investigated, whe...

A modified strip-yield model has been developed to simulate the plasticity-induced crack closure under the constant amplitude (CA) and a single overload loading conditions. The paper focuses on the simulation of the near tip crack profiles and stress distributions during the fatigue process. Detailed information on near-tip stress and displacement fields at the maximum load (Pmax), the minimum ...

The mechanisms of fatigue-crack propagation in ceramics and intermetallics are examined through a comparison of cyclic crack-growth behavior in ductile and brittle materials. Crack growth is considered to be a mutual competition between intrinsic mechanisms of crack advance ahead of the crack tip, which promote crack growth, and extrinsic mechanisms of crack-tip shielding behind the tip, which ...