非连续变形分析中时间步及弹簧刚度取值研究

发布时间：2018-06-18 08:39

本文选题：非连续变形分析(DDA) + 惯性力　；参考：《岩土力学》2015年03期

【摘要】：非连续变形分析(DDA)是一种隐式求解的动力学计算方法,且采用在块体界面加减刚硬弹簧的方式来满足块体界面无张拉和无嵌入的接触准则,其中时间步长和弹簧刚度两个物理量的取值直接影响DDA的计算结果。基于对DDA时间步和弹簧刚度在程序运行过程中的调整策略和块体接触的简化力学概念模型,研究了惯性力在DDA收敛求解中的作用过程。采用数值模拟试验对自由落体和斜面单滑块模型在3种力学状态下的相关力学问题进行了数值模拟研究,通过对自由落体运动的模拟,研究了时间步长单一因素对计算结果的影响规律,并初步确定了时间步长的合理取值区间。在此基础上,采用斜面单滑块模型,研究了时间步长和弹簧刚度对计算结果的共同影响,确定了不同时间步长条件下弹簧刚度的合理取值区间。研究成果表明,合适的时间步长和弹簧刚度的取值组合构成一个单连通参数取值域,当时间步和弹簧刚度的取值组合位于此"域"范围内时,DDA的计算结果是合理的。
[Abstract]:The discontinuous deformation analysis (DDA) is a dynamic calculation method for implicit solution. The method of adding and reducing rigid springs on the block interface satisfies the open and non embedded contact criteria of the block interface. The time step and the spring stiffness of the two physical quantities directly influence the calculation results of the DDA. Based on the time step and the spring of the DDA, A simplified mechanical conceptual model of the adjustment strategy and the contact of the block in the process of the program is studied. The action process of the inertia force in the solution of DDA convergence is studied. Numerical simulation is used to simulate the related mechanical problems of the free falling body and the inclined single slider model under 3 Mechanical States, through the free falling body. The effect of the single factor of time step on the calculation results is studied, and the reasonable interval of the time step is preliminarily determined. On this basis, the common influence of the time step and the spring stiffness on the calculation results is studied by the single slide block model of the inclined plane, and the combination of the spring stiffness under different time steps is determined. The results show that the suitable time step and the combination of spring stiffness constitute a single connected parameter range. When the time step and the spring stiffness are combined in the "domain" range, the results of the DDA are reasonable.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室非连续变形中心;
【基金】：国家重点基础研究发展计划(973)项目(No.2011CB710600) 国家自然科学基金资助项目(No.51179014)
【分类号】：TU45

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