Mathematics – Logic
Scientific paper
May 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001e%26psl.187..367s&link_type=abstract
Earth and Planetary Science Letters, Volume 187, Issue 3-4, p. 367-379.
Mathematics
Logic
41
Scientific paper
The formation of a continuous crystal network in magmas and lavas can provide finite yield strength, τy, and can thus cause a change from Newtonian to Bingham rheology. The rheology of crystal-melt suspensions affects geological processes, such as ascent of magma through volcanic conduits, flow of lava across the Earth's surface, melt extraction from crystal mushes under compression, convection in magmatic bodies, and shear wave propagation through partial melting zones. Here, three-dimensional numerical models are used to investigate the onset of `static' yield strength in a zero-shear environment. Crystals are positioned randomly in space and can be approximated as convex polyhedra of any shape, size and orientation. We determine the critical crystal volume fraction, φc, at which a crystal network first forms. The value of φc is a function of object shape and orientation distribution, and decreases with increasing randomness in object orientation and increasing shape anisotropy. For example, while parallel-aligned convex objects yield φc=0.29, randomly oriented cubes exhibit a maximum φc of 0.22. Approximations of plagioclase crystals as randomly oriented elongated and flattened prisms (tablets) with aspect ratios between 1:4:16 and 1:1:2 yield 0.08<φc<0.20, respectively. The dependence of φc on particle orientation implies that the flow regime and resulting particle ordering may affect the onset of yield strength. φc in zero-shear environments is a lower bound for φc. Finally the average total excluded volume is used, within its limitation of being a `quasi-invariant', to develop a scaling relation between τy and φ for suspensions of different particle shapes.
Cashman Katharine V.
Fremouw S.
Manga Michael
Saar Martin O.
No associations
LandOfFree
Numerical models of the onset of yield strength in crystal-melt suspensions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Numerical models of the onset of yield strength in crystal-melt suspensions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Numerical models of the onset of yield strength in crystal-melt suspensions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-926062