Hi 

The problem I have recently faced is to find a relationship
between the amplitude of crack tip opening angle (CTOA) in a breathing crack
and the stress intensity factor (SIF) in bending displacement of a cantilevered
non-propagating cracked beam. Actually what I am looking for is the analytical
equation which relates CTOA to SIF; something like the one that exists for
crack tip opening displacement (CTOD).
I checked both Andreson’s and Broek’s fracture books and also lots of papers in
the related area but did not find the equation I am looking for. I would be
thankful if anyone could help me with this or introduce me some references. Your answer
is highly appreciated.