Experimental analysis and modelling of fatigue crack initiation mechanisms

Side Effects of Shot Peening on Fatigue Crack Initiation Life

Shot peening beneficial effects on fatigue life of mechanical components are well known. However, there are some reports in the literature that indicate inappropriate shot peening parameters tend to reduce the fatigue life. It is therefore, the purpose of this study to find a logical quantitative justification for these observations. Using finite element method, a dynamic elastic-plastic simula...

The Role of Microtexture of Fatigue Lifetime Variability and Crack Initiation Mechanisms (preprint)

Fatigue Crack Initiation and Multiplication of Unnotched Titanium Matrix Composites

ÐFatigue crack initiation and multiplication of the unnotched SCS-6 silicon carbide ®ber-reinforced titanium matrix composites with di€erent matrix and interfacial properties have been investigated experimentally and analytically. Ti±15V±3Al, Ti±6Al±4V, and Ti±22Al±23Nb were chosen as matrix materials. The initiation and propagation of each individual matrix crack as a function of fatigue cycle...

Thermal activation of fatigue crack growth: analysing the mechanisms of fatigue crack propagation in superalloys

A method for deriving apparent activation energies, Eapp, for fatigue crack growth (FCG) is presented. It is shown how these Eapp values can be used to analyse the main underlying mechanism causing the progression of the crack. The Eapp values for fatigue crack growth in air and vacuum, and with and without a dwell are obtained for a range of Ni based superalloys for turbine disc applications. ...

Modelling Mode I Crack Initiation in Composites under Fatigue Loading Using Interface Elements

Modelling quasi-static crack growth with interface elements is a widely accepted technique [1-2]. Interface elements are inserted into the finite element mesh along possible crack paths. The interface elements are characterised by a traction-displacement curve. When a specific maximum stress is reached, the interface element undergoes a softening process until the critical fracture energy has b...