INVESTIGATIONS OF FRACTURE INSTABILITY IN CRACK-GROWTH FOR SEVERAL METALS .2. AN ENERGY APPROACH FOR FRACTURE INSTABILITY ANALYSIS OF CRACK-GROWTH

An energy approach is presented to predict fracture instability using elastic-plastic internal energy in structures, the physical behaviour of crack growth, dynamic effects in the process of unstable crack grow th and intense strain region near the crack tip are considered. The pr actical forms of the approach have predicted correctly fracture instab ility of tests with three-point bending specimens (3PB specimen) and c ompact specimens (CT specimen) under highly stiff supporting system, b ut 'tearing modulus criterion' gave incorrect estimations which were s hown in part I [1].