Subcritical crack growth in brittle material at gas turbulence effect on aggressive species transport to crack tip
✍ Scribed by Rafael Salganik; Dan Naot; Victor Gotlib
- Publisher
- Springer Netherlands
- Year
- 1995
- Tongue
- English
- Weight
- 401 KB
- Volume
- 72
- Category
- Article
- ISSN
- 1573-2673
No coin nor oath required. For personal study only.
✦ Synopsis
A phenomenon typical for brittle materials, such as glasses, ceramics and rocks, is subcritical crack growth (SCG), when the crack length l is slowly increased before reaching, under an appropriate loading, a critcial length, l c, above which a spontaneous crack growth occurs. The SCG is highly sensitive to the presence of water in the environment, which affects, as an aggressive species, the rate of rupture of bridging bonds at the crack tip through a kind of hydrolytic reaction [1,2]. We will consider SCG in a humid gas environment at a constant temperature. Most typically SCG is observed as three-regime crack velocity, v, vs. stress intensity factor (SIF), K z = K, behavior under opening (mode I) loading above a threshold value of K but below a critical value K = K corresponding to l,. Regime 1 is the reaction controlled sharp increase in v with increasing K. Regime 2 is almost unvarying v decided by water vapor transport to the crack tip. Regime 3 is a more sharp (compared to Regime 1) increase in v with increasing K independent (or nearly independent) on water vapor concentration [ 1,2].