Fracture Mechanics Approach to Stress Corrosion

Fracture Mechanics Approach to Stress Corrosion Stress intensity factor (ksiVin)... 

Andrews, E.H. (September 1966) Fracture mechanics approach to corrosion stress cracking in plastics in Proceedings of the Conference on the Physical Basis of Yield and Fracture, Oxford, (ed. A.C. Strickland), Institute of Physics The Physical Society London, p. 127. 

The stress corrosion resistance of maraging steel has been evaluated both by the use of smooth specimens loaded to some fraction of the yield strength and taking the time to failure as an indication of resistance, and by the fracture mechanics approach which involves the use of specimens with a pre-existing crack. Using the latter approach it is possible to obtain crack propagation rates at known stress intensity factors (K) and to determine critical stress intensity factors (A iscc) below which a crack will not propagate (see Section 8.9). 

For an edge crack, the crack length is a, for a center crack the crack length is 2 a. Most of the past research of stress corrosion cracking utilizes the fracture mechanics approach in which the relation between the initially applied stress, stress intensity factor Ki and the time to failure of pre-cracked specimen is observed. The time to failure increases as Ki decreases from the level required for the fracture to occur (Kic, fracture toughness) to a threshold level (Kiscc) below which SCC does not occur. 

---