基于球面沃罗诺伊的颗粒表面离散与重构方法  

A SPHERICAL VORONOI TESSELLATION-BASED APPROACH FOR PARTICLE SURFACE DISCRETIZATION AND RECONSTRUCTION

作　　者：吴峰 黄林冲 赖正首 WU Feng;HUANG Lin-chong;LAI Zheng-shou(School of Aeronautics and Astronautics Engineering,Sun Yat-sen University,Shenzhen 518107,China;School of Intelligent Systems Engineering,Sun Yat-sen University,Shenzhen 518107,China)

机构地区：[1]中山大学航空航天学院,深圳518107 [2]中山大学智能工程学院,深圳518107

出　　处：《工程力学》2024年第9期245-256,共12页Engineering Mechanics

基　　金：国家自然科学基金项目(51909289,51978677);国家自然科学基金国际(地区)合作与交流项目(NSFC-FWO)(52111530089)。

摘　　要：提出了一种基于球面沃罗诺伊、球谐函数及计算机断层扫描的岩土颗粒表面离散与重构方法。该方法在球坐标参数空间采样的基础上,采用带权重的加权球面质心沃罗诺伊对采样点进行自适应分布,并给出了两种表面重构的加权公式:基于径向距离加权和基于曲率加权。该方法适用于如二次曲面或球谐函数等隐式函数描述的颗粒表面的网格化离散,以及通过计算机断层等方法得到的颗粒原始表面的优化重构。其优点是:可以重构得到任意数量节点的表面网格;提供了一种控制表面网格节点分布密度的灵活方法。对重构后的颗粒进行形状参数分析和离散元模拟,分析并验证了该方法应用于颗粒表面离散与重构的有效性与准确性,其可以简化复杂的表面网格、减少颗粒表面节点,同时保证形状参数的误差在较小的范围,显著减少离散元模拟的时间成本,而不影响最终模拟结果。A spherical Voronoi tessellation and spherical harmonics-based approach is proposed for reconstructing high-quality particle surface from X-ray computed tomography.This approach adopts the spherical coordinate system for particle surface parametrization and utilizes weighted spherical Voronoi tessellation to adaptively adjust the locations of the sampled parametric points.Two formulations of weights for the Voronoi seeds are developed,namely one based on radial distance and one based on curvature.The approach proposed can be applied to the surface discretization of particles represented by implicit functions,such as quadrics or spherical harmonics,and to the reconstruction of particle surfaces that are originally obtained from imaging technical such as X-ray computed tomography.It has two advantages:It can provide surface meshes with any number of nodes;It offers a flexible option to control the distribution of the surface mesh nodes.The shape characterization analysis and discrete element simulation of the reconstructed particles are carried out to analyze and to verify the effectiveness and accuracy of the proposed approach.Analysis results indicate that:the approach can effectively simplify complex surface meshes,reduce particle surface nodes,and preserve shape morphology descriptors;thusly,significantly reduce the time cost of discrete element simulation.

关 键 词：岩土工程 表面重构 离散元 沃罗诺伊 球谐函数 

分 类 号：TU43[建筑科学—岩土工程]