| Summary: | 碩士 === 國立中央大學 === 土木工程學系 === 84 === this research follows the theory of discrete element method
built by Cundall (1971), and applies this concept to granular
mechanics. the granularparticles are assumed as 2-D rigid
circular discs. Comparison is made betweenthe penalty spring and
the Hertz spring and the penalty spring is employed in this
research. Penalty spring is found very efficient for the
convergence of a granular system. Various spring stiffnesses are
used to overcome the problem of squash spring which may occur in
a system of various disc diameters. To simulate a nature
deposit, this research develops an auto packing method which
enhances the applicability of the developed code in engineering
problem. In order to study the difference of mechanical
behavior between the micro- scopic and macroscopic scales,
examples simulate the rest angle and the activestate of sand are
analyzed. For the same particle-size distribution curve, it is
found that internal friction angle does not play a major factor
as expected,In addition, for the active failure case, a regular
packing shows a plane failure surface, while a random packing
presents a smoothly curve plane, whichis similar to the
assumption of a logarithmic spiral by Terzaghi and Peck (1967).
This research shows that the 2-D circular discs can successfully
simulate a granular system and engineering analyses.
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