A damage model of creep crack growth in polycrystals
Journal
Acta Metallurgica
Journal Volume
31
Journal Issue
10
Pages
1675-1687
Date Issued
1983
Author(s)
Abstract
A model for the growth of cracks by cavitation has been developed in which the effect of a viscous constraint has been considered. The important parameters are the grain size (l) and viscosity (η) of the material, the applied stress intensity factor (K) and the size of the damage zone (z), as well as the spacing of the cavities (λ ) and the size at which they coalesce ([ifA1.f). The velocity of the crack is predicted by this model to be proportional to K and inversely proportional to η. Its dependence upon the grain size is more complex and can vary between a ̇ ∞ l- 5 2 and a ̇ ∞ l 1 2. The influence o been shown to be important only for small damage zones, and high values of both the relative cavity spacing (l/λ) and the cavity area at coalescence. Otherwise, the crack velocity tends to the values predicted in the absence of constraint. © 1983.
SDGs
Type
journal article