SC-CO2 phase change are mainly responsible for fracture post-instability, which dominates fracture propagation in SC-CO2 fracturing.
A shell element enhanced by embedded discontinuities is developed to improve coarse-mesh accuracy in terms of fracture initiation prediction and to regularize the post-instability response.
In this paper, laboratory experiments conducted on polymethyl methacrylate (PMMA) are used to study the post-instability induced by SC-CO2 phase change on fracture dynamic propagation.
The results of this study indicate that the presence of differential pressure can have a significant influence on the equilibrium path, the number and location of unstable points, and the post-instability behavior.
It is shown that for a plain pipe (with no end-mass), non-planar post-instability oscillations can be reduced to planar periodic oscillations for a range of base excitation frequencies and amplitudes.
The finite-element meshes where constant-strain crack band elements in the localized regions are combined with the continuous elements everywhere else yield, on the other hand, a computationally stable and accurate post-instability response for a wide range of crack-band element widths.
Attention is focused on bifurcational systems under follower loading exhibiting a trivial stable fundamental path from which a post-divergence or post-oscillatory instability may occur.
9) Post inflammatory instability of the vertebral spine.
Spontaneous hydrolysis and oxidation are examples of the most commonly found damage that cause post mortem instability of nucleic acids.
After all, Putin's reason for telling Saddam he could stay in his party role was to avoid post-regime instability in Iraq.
Mr. Stevens understood that Libyans had suffered under Col. Muammar el-Qaddafi, and that conflict and post-revolutionary instability were to be expected.
