Abstract
The operational conditions in next generation power plants and other
high temperature applications such as turbine blades in jet engines
demand the component to perform under extreme conditions where metallic
materials show time dependent deformation under cyclic loading
conditions. Under creep-fatigue loading condition, the crack tip is
exposed to both time dependent and independent plastic deformation.
Conventional crack characterizing parameters such as (C t ) , avg has
shown good correlation with dominant damage based crack velocity, (d
a/d t ) avg . However, the true definition or prediction of crack
driving forces under such scenario are vague due to limited theoretical
validity of the conventional crack tip characterizing parameters, such
as J or C t. In this work, the concept of
configurational forces are applied for the first time to understand the
creep-fatigue crack growth behaviour. The crack growth is simulated
using node-release technique and the configurational forces are
calculated using post processing the finite element results for
calculation of dJ/dt.