Ultra High Speed Discrete Element Simulation Engine

• Main Authors: Chi-Yu Wu, 吳騏宇
• Other Authors: Yo-Ming Hsieh
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/56zhu8

碩士 === 國立臺灣科技大學 === 營建工程系 === 106 === Discrete Element Method (DEM) is a numerical method that has many applications in geotechnical engineering. It divides the continuous time into many time steps and calculate the physical behavior of discrete elements in each time step. Accurate DEM analyses needs to calculate many elements and collisions between them with tiny time discretization and thus many time steps. Therefore, simulations using DEM takes too long to be practical. This study develops a program that utilizes graphical processing unit (GPU) to conduct DEM analyses with reduced computing time. This study consists of the following four main steps. The commercial software PFC3D .is firstly studied to understand its inner work. A GPGPU code is then developed using object-oriented programming to allow flexibility and extensibility. The calculation results from the developed code are compared and validated with PFC3D. Afterwards, several collision detection algorithm are studied and one is then selected to be implemented in the program. Finally, the code is extended with a new computing engine that uses OpenCL to drive the GPU device to execute the full discrete elements analysis. This study further compares the performance of the DEM calculated by GPU and CPU under different problem sizes and different floating-point precisions. It is concluded that the DEM performance using GPU can be 100 times better than CPU when the number of discrete elements is large. It is also concluded that the performance of the developed code is memory bound (by the memory bandwidth) rather than bound by the compute capability (CPU bound).