In the past, contact model in the combined finite-discrete element method (FDEM) does not include the influence of the tangential contact interaction, and the deficient model associated with the contact force can seriously degrade the computing accuracy. In order to overcome this defect, an improved FDEM is developed in this work. The potential contact mechanism is implemented to calculate the normal contact force; meanwhile, the force-displacement law by coupling the classical Mohr–Coulomb type frictional algorithm and the rotation transformation algorithm is applied for the accurate computation of the tangential contact force. Consequently, a holonomic system of the calculation algorithm for the contact interaction is proposed, accounting for the influence of the tangential contact force. The performance of the approach is validated with well-known benchmarks including a frictional numerical test, the dynamic response of the block under the seismic excitation, a sliding/toppling test of a joint rock slope, a numerical simulation for joints structure affecting a sliding rock mass and the 2008 Donghekou Landslide trigged by the Wenchuan Earthquake. The results are compared against the experimental data and analytical solutions. Excellent agreements between the computational result and existing measurements show that the proposed approach has an outstanding ability to describe the complex mechanical properties among the separate entities.

中文翻译：

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组合有限元法的切向力模型

过去，组合有限离散元法（FDEM）中的接触模型不包括切向接触相互作用的影响，与接触力相关的模型不足会严重降低计算精度。为了克服这个缺陷，在这项工作中开发了一种改进的 FDEM。实现电位接触机制，计算法向接触力；同时，结合经典的Mohr-Coulomb型摩擦算法和旋转变换算法的力-位移定律用于切向接触力的精确计算。因此，考虑了切向接触力的影响，提出了一个完整的接触相互作用计算算法系统。该方法的性能得到了著名的基准测试的验证，包括摩擦数值试验、块体在地震激励下的动态响应、节理岩质边坡的滑动/倾倒试验、节理结构影响滑动岩石的数值模拟2008年汶川地震引发的东河口滑坡。将结果与实验数据和分析解决方案进行比较。计算结果与现有测量结果之间的出色一致性表明，所提出的方法具有描述单独实体之间复杂机械性能的出色能力。2008年汶川地震引发的滑动岩体与东河口滑坡的节理结构数值模拟[J]. 将结果与实验数据和分析解决方案进行比较。计算结果与现有测量结果之间的出色一致性表明，所提出的方法具有描述单独实体之间复杂机械性能的出色能力。2008年汶川地震引发的滑动岩体与东河口滑坡的节理结构数值模拟[J]. 将结果与实验数据和分析解决方案进行比较。计算结果与现有测量结果之间的出色一致性表明，所提出的方法具有描述单独实体之间复杂机械性能的出色能力。