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arXiv · 1202.6272

Jammed frictional tetrahedra are hyperstatic

Max Neudecker·Stephan Ulrich·Stephan Herminghaus·Matthias Schröter
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Abstract

We prepare packings of frictional tetrahedra with volume fractions {\phi} ranging from 0.469 to 0.622 using three different experimental protocols under isobaric conditions. Analysis via X-ray micro-tomography reveals that the contact number Z grows with {\phi}, but does depend on the preparation protocol. While there exist four different types of contacts in tetrahedra packings, our analysis shows that the edge-to-face contacts contribute about 50% of the total increase in Z. The number of constraints per particle C increases also with {\phi} and even the loosest packings are strongly hyperstatic i.e. mechanically over-determined with C approximately twice the degrees of freedom each particle possesses.

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Max Neudecker, Stephan Ulrich, Stephan Herminghaus, Matthias Schröter. 2012-02-28. Jammed frictional tetrahedra are hyperstatic. https://doi.org/10.1103/physrevlett.111.028001

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