中文摘要：

非连续变形分析（DDA）方法非常适合应用于模拟高度离散化的岩石块体系统的力学行为。然而,传统采取隐式时间积分方案的DDA方法,在运算过程中需要集成总体刚度矩阵和求解矩阵方程,这直接导致计算效率的降低,尤其在求解大规模非连续问题时。因此,提出一种基于显式时间积分的二维显式DDA方法。在求解过程中,不需要集成总体刚度矩阵和求解大型代数方程组。在求解加速度时,由于采用协调质量矩阵,可以分块求解,求解过程简单省时。仍沿用原DDA的开闭迭代算法,可确保块体间约束的准确施加,保证了求解精度。最后,通过几个典型算例,证实显式DDA的正确性和鲁棒性。

英文摘要：

Discontinuous deformation analysis method（DDA） is very suitable for modeling the mechanical behaviors of highly discrete rock block system. However,it need to integrate the global stiffness matrix and solve the matrix equation for the traditional DDA that adopts the implicit time integration scheme. This will result in the decrease of calculation efficiency,especially in solving the large-scale discontinuous problems. Therefore,an explicit version of two-dimensional DDA is proposed based on the explicit time integration scheme. There is no need to integrate the global stiffness matrix and solve the large-scale simultaneous algebraic equations in the solving process. Block elimination method is used to calculate the acceleration as the result of adoption of consistent mass matrix,which is simple and time-saving. The open-close iteration is still adopted to ensure the right arrangement of constraints. At last,the correctness and robustness of explicit DDA is confirmed by several classic numerical examples.