In the simulation of discontinuous block systems, the discrete element method (DEM) has better computational efficiency and convergence than the finite element method (FEM). When several DEM particles are bonded together with parallel bonds (the bonded particle model, BPM), various shapes and block fractures can be simulated. The main aim of the BPM is to simulate a continuous material in which the stress distribution is continuous. Since the existing stress result for a single particle is an average value over the particle’s area, stress results do not exist in the area between particles. In this paper, the stress value for a single two-dimensional DEM particle is deduced. A stress recovery procedure with a linear stress function for a triangular element generated by the centroids of three bonded particles is proposed. In this way, the recovered stress field for the whole mesh composed of all triangular elements is continuous. A stress gradient exists in the whole mesh. This can also provide more accurate stress values for judging a fracture inside a block. Symmetrical and asymmetrical models are simulated by the BPM and FEM. Similar to the FEM results, the recovered stress results for the BPM can describe the stress distribution in the simulated continuous blocks. For the model with the theoretical stress solution, the recovered result and the theoretical solution coincide well.

在不连续块系统的仿真中，离散元方法（DEM）比有限元方法（FEM）具有更好的计算效率和收敛性。当几个DEM粒子通过平行键结合在一起（结合粒子模型，BPM）时，可以模拟各种形状和块状断裂。BPM的主要目的是模拟应力分布连续的连续材料。由于单个粒子的现有应力结果是整个粒子面积的平均值，因此应力结果不存在于粒子之间的区域中。本文推导了单个二维DEM颗粒的应力值。针对由三个键合颗粒的质心产生的三角形元素，提出了一种具有线性应力函数的应力恢复程序。通过这种方式，由所有三角形元素组成的整个网格的恢复应力场是连续的。应力梯度存在于整个网格中。这也可以提供更准确的应力值来判断块体内的断裂。对称和非对称模型由BPM和FEM进行模拟。与FEM结果相似，BPM的恢复应力结果可以描述模拟连续块中的应力分布。对于具有理论应力解的模型，恢复结果与理论解非常吻合。与FEM结果相似，BPM的恢复应力结果可以描述模拟连续块中的应力分布。对于具有理论应力解的模型，恢复结果与理论解非常吻合。与FEM结果相似，BPM的恢复应力结果可以描述模拟连续块中的应力分布。对于具有理论应力解的模型，恢复结果与理论解非常吻合。