T as a Static/Fatigue/Dynamic Crack Growth Parameter

Professor Albert S. Kobayashi
Department of Mechanical Engineering
University of Washington

Sponsored by the Department of Engineering Mechanics

Date:  Wednesday, April 15, 1998
Time:  2:00 p.m.
Place:  W128 Nebraska Hall

The possibility of using a T integral, which is a J-integral based on the incremental theory of plasticity, as a ductile fracture criterion is explored through experimental and numerical analyses of fracture tests. Moire interferometry and finite element (FE) analysis were used to determine T integral values in 2024-T3 SEN, CN and CT fracture specimens with stable straight and curved crack growths, with low-cycle fatigue crack growth and with rapid crack propagation. The results obtained to date show that Treached the same steady state value regardless of the loading condition or crack path. Moreover, the terminal velocity of a rapidly propagating crack was achieved at a maximum T value. These results are in conflict with the traditional findings of elastic-plastic fracture mechanics.