An efficient and robust GPGPU-parallelized contact algorithm for the combined finite-discrete element method

An efficient and robust GPGPU-parallelized contact algorithm for the combined finite-discrete element method

In this study, an efficient and robust GPGPU (general purpose graphic processing unit)-parallelized algorithm is proposed for contact force calculation for the three-dimensional combined finite-discrete element method (3D FDEM). The contact force model is energy-conserving and avoids the issues that the mesh-dependence of contact force in the original contact algorithm proposed by Munjiza. The contact force calculation is based on the determination of the geometrical features of the overlapped region between two particles, which can be easily obtained by performing the face–particle intersection calculations consecutively. The contact damping and contact friction are also implemented. Based on Compute Unified Device Architecture (CUDA), the proposed contact algorithm can be parallelized with much less thread unbalance and register usage than the existing energy-conserving contact algorithms due to the simplified computational process. Several numerical tests are performed to validate the efficiency and effectiveness of the proposed contact algorithm. The contact friction model is validated against theoretical solutions with a block sliding test, and the results show that the proposed contact algorithm outperforms the original contact algorithm in both normal and friction force evaluation. For both quasi-static and dynamic scenarios, the simulated results are in good agreement with those generated by the original contact algorithm, as well as the experimental measurements. The computational efficiency tests show that the computation time is linearly proportional to the number of potential contact pairs, and the speedup ratio of the parallelized version of proposed contact algorithm relative to the serial version of original contact algorithm can reach up to 565.1 (Nvidia Quadro GP100), which indicates the proposed contact algorithm is capable to be employed in the simulation of large-scale problems. Besides, the proposed contact algorithm can be applied to the cases where the polyhedrons with more than four vertexes are employed. • An efficient and robust GPGPU-parallelized contact algorithm is proposed. • Proposed contact algorithm is mesh-independent and energy-conserving. • Feasibility in both quasi-static and dynamic scenarios is validated. • Speedup ratio of 565 relative to serial version of original contact algorithm is obtained.

在这项研究中，提出了有效且稳健的GPGPU（通用图形处理单元） - 平行算法用于三维合并有限的二氧化碳元素方法（3D FDEM）的接触力计算。避免了Munjiza提出的原始接触算法中接触力的网格依赖性的问题。可以根据统一的统一装置体系结构（CUDA）实施两个粒子之间的重叠区域，可以通过触摸舞和接触摩擦来轻松获得。由于简化的计算过程，与现有的支持能量的触点算法相比，线程不平衡和注册使用情况更少。通过验证拟议的接触算法的有效性和有效性。对于准静态和动态场景，模拟结果与原始触点算法产生的结果均吻合，以及实验测量结果。 NVIDIA Quadro GP100），这表明所提出的接触算法能够在大规模问题的模拟中进行。应用了多个超过四个顶点的病例。方案已被验证•相对于原始联系算法的串行版本的加速比率为565。