The Approximate Solutions For The Interaction Of A Plane Stress Crack With An Arbitrary-shaped Inclusion And The Application Of The Plasticity-corrected Stress Intensity Factor On Fatigue Crack Growth Under Cyclic Compression

It is well know that both an inclusion and a plastic deformation zonearound a crack-tip will have a crucial effect on the behavior of the fractureand the fatigue crack growth(FCG). Although it has been extensivelyresearched on this field, some issues still remain to have a significantbreakthrough. On the basis of the Eshelby inclusion theory and thetransformation toughening theory, the following research results have beengot in this thesis:(1) An approximate solution has been derived to describethe interaction of an I/II plane stress crack with an arbitrary-shapedinclusion, which has a fairly good accuracy compared with FE-results.(2)Considering the similarity between the inclusion and the plastic zonethrough the stress equivalence principal of the Eshelby inclusion theory, aclosed-form expression of the plasticity-corrected stress intensity factor(PC-SIF) has been acquired for mode-I crack under small-scale yielding(SSY) conditions.(3) Through applying the concept of the PC-SIF into thereal case of cyclic compression as the mechanical driving force parameter,the influence of the factors such as the applied stress amplitude, meanstress, cyclic load ratio, overload and underload on FCG has beensuccessfully analyzed.