Displacement Accuracy of Discontinuous Deformation Analysis Method Applied to Sliding Block
Displacement Accuracy of Discontinuous Deformation Analysis Method Applied to Sliding Block
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DOI：
10.1061/(asce)0733-9399(2002)128:11(1158
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发表时间：
2002-10
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影响因子：
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通讯作者：
David Doolin;N. Sitar
中科院分区：
文献类型：
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作者：
David Doolin;N. Sitar
不连续变形分析（DDA）是为计算裂隙岩体大变形而发展起来的一种离散元方法。在本文中，我们提出了平面（二维）问题的DDA基本理论的另一种推导，并利用灵敏度分析解决了滑动块的DDA方法的准确性。不同参数下的分析结果表明，摩擦滑块位移的残差和相对误差受仿真初始时间步长的摄动控制。此外，我们揭示了由DDA惩罚公式引起的系统误差。总的来说，溶液的初始扰动随着摩擦角的减小和接触惩罚的增大而减小，并且与直觉相反，随着时间步长的增大而减小。所有分析都表明，系统的长跳动行为趋向于解析解，与初始扰动无关。长跳动模拟的结果精度足以解决所有工程问题。
Discontinuous deformation analysis (DDA) is a discrete element method that was developed for computing large deformation in fractured rock masses. In this paper, we present an alternative derivation of the basic theory of DDA for planar (two-dimensional) problems, and we address the accuracy of the DDA method for sliding blocks using sensitivity analyses. Results of analyses with different parameters show that the residual and relative errors in the displacement of a frictional sliding block are controlled by the perturbation in the initial time steps of the simulation. In addition, we expose a systematic error induced by the DDA penalty formulation. Overall, the initial perturbation of the solution decreases with decreasing friction angle and increasing contact penalty and, counterintuitively, decreases with increasing time step size. All analyses show that the long runout behavior of the system trends toward the analytic solution, independent of the initial perturbation. The resulting precision of the long runout simulation is more than sufficient for all problems of engineering interest.