Browsing by Author "Chiu, Chia-Chi"

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DEM simulation of planar sliding using a particulate interface model considering velocity-dependent friction
(2019-08-01)
Chiu, Chia-Chi
;
Weng, Meng-Chia
;
土木工程學系
;
Department of Civil Engineering
Planar sliding is a typical failure mode of landslides, in which an unstable rock block slides along a weak plane, resulting in a rapid movement. This study proposes a particulate interface model (PIM) that considers velocity dependent friction behavior to simulate the planar sliding behavior of the particulate DEM. To validate the performance of the proposed model, the results of a DEM simulation of the planar sliding of a rigid block are compared with the analytical dynamic solution. The results reveal that the PIM simulation is consistent with the analytical dynamic solution with or without consideration of the velocity-dependent friction law. The ordinary contact model does not accurately reflect the theoretical dynamics owing to the high resistance. The smooth joint model underestimated the shear resisting force of the interface and yielded excessively high velocity and displacement of the block. With respect to the deposition distribution, the different interface models yielded the various velocities before impact, and therefore various failure patterns of the block and appearances of the deposition. The block velocity significantly influences the number of cracks. The results of the analysis reveal that the PIM can capture the planar sliding and deposition behavior of particulate DEM.
Simulating interface characteristics by using a particulate interface model of a discrete element method
(2019-05-01)
Chiu, Chia-Chi
;
Weng, Meng-Chia
;
土木工程學系
;
Department of Civil Engineering
This paper proposes a particulate interface model to simulate the interface by using a particulate discrete element method. Six modifications are adopted in the numerical calculations to improve the stability and accuracy. The interface model provides two failure criteria: one is the Mohr Coulomb failure criterion and the other is the Barton-Bandis shear strength criterion. To verify the proposed model, the failure envelope, the shear-displacement curve, the closure curve, and the dilation curve were analyzed and simulated. The simulations demonstrated good agreement with the theoretical curves. The influence of the particle size was also investigated; the results proved that the quantity or size of the particle did not affect the performance of the proposed model. Finally, a rock bolt pull-out problem was simulated. The results proved that the proposed interface model can reasonably predict the shear stress acting on the interface between the rock bolt and rock.