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AN ALTERNATIVE ANALYTICAL APPROXIMATION OF THE C t PARAMETER
Author(s) -
Adefris,
McDowell,
Saxena
Publication year - 1998
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1046/j.1460-2695.1998.00531.x
Subject(s) - creep , materials science , exponent , mechanics , power law , transient (computer programming) , fracture (geology) , diffusion creep , measure (data warehouse) , limit (mathematics) , structural engineering , forensic engineering , mathematics , computer science , composite material , physics , mathematical analysis , engineering , statistics , microstructure , philosophy , linguistics , database , grain boundary , operating system
The C t parameter has proven very useful in correlations of creep crack growth behaviour under both transient and steady state creep conditions. In this paper, we investigate the implications of adopting a different definition of the creep zone based on an absolute measure of creep strain rather than a measure that is relative to the elastic strain. The analytical equations for small‐scale creep and transition times from small‐scale creep to extensive creep conditions are derived for the C t parameter using this alternative definition, considering both primary and secondary creep strain. It is shown that this alternative definition gives a reasonable starting point for the theory, approximately in accordance with the transient evolution of the C t parameter based on the more conventional definition of the creep zone, and removes the somewhat artificial limit of applicability imparted by the classical creep zone definition used in creep fracture mechanics. Accordingly, diffusional creep processes with a power law exponent n ≤ 3 are admitted in the C t description.