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Mathematical Problems in Engineering
Volume 2017, Article ID 7480937, 9 pages
https://doi.org/10.1155/2017/7480937
Research Article

Study on the Damping of the Discontinuous Deformation Analysis Based on Two-Block Model

1School of Civil Engineering, Wuhan University, Wuhan 430072, China
2School of Civil Engineering and Architecture, Nanchang University, Nanchang 330031, China
3Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources, Yangtze River Scientific Research Institute, Wuhan 430010, China

Correspondence should be addressed to Qinghui Jiang; nc.ude.uhw@2791hqj

Received 24 April 2017; Accepted 21 June 2017; Published 18 July 2017

Academic Editor: Michele Betti

Copyright © 2017 Xixia Feng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The deformation and failure of rock mass is a process of energy dissipation; the damping of DDA is a very important and basic problem. The correctness and effectiveness of DDA rely on the appropriate values of the numeric controlling parameters like time interval, spring stiffness, and assumed maximum displacement ratio , and the contact using the penalty method is the core content of DDA. A mechanical model of two contact blocks loaded with the normal force acting along one side of block boundary is established to study the DDA damping problem, which involves the contact and eliminates the influence of some numeric control parameters (e.g., ). Based on the Newmark method and the theory of DDA, the motion equations of two-block system can be established, and then the relationship of some numeric control parameters and the influence of damping can be obtained. The algorithmic damping increases with the increasing of time interval. Given a very small time interval, the spring stiffness may have no obvious effect on the algorithmic damping. The numerical results reveal that the essence of time interval influencing the open-close iteration is the fact that the algorithmic damping is mainly controlled by time interval.