Abstract :
Themaximum energy release rate criterion,
i.e., Gmax criterion, is commonly used for crack propagation
analysis. However, this fracture criterion is
based on the elastic macroscopic strength of materials.
In the present investigation, a modification has been
made to Gmax criterion to implement the consideration
of the plastic strain energy. This criterion is extended
to study the fatigue crack growth characteristics
of mixed mode cracks in steel pipes. To predict crack
propagation due to fatigue loads, a new elasto-plastic
energy model is presented. This new model includes
the effects of material properties like strain hardening
exponent n, yield strength σy and fracture toughness
and stress intensity factor ranges. The results obtained
are compared with those obtained using the commonly
employed crack growth law and the experimental data.
