Zhou Xiaodong, Jin Dongzhao, Ge Dongdong, Chen Siyu, You Zhanping
Rizhao City Transportation Bureau, Rizhao 276800, China.
Department of Civil, Environmental, and Geospatial Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931-1295, USA.
Materials (Basel). 2023 Apr 13;16(8):3073. doi: 10.3390/ma16083073.
The widely used simple cubic-centered (SCC) model structure has limitations in handling diagonal loading and accurately representing Poisson's ratio. Therefore, the objective of this study is to develop a set of modeling procedures for granular material discrete element models (DEM) with high efficiency, low cost, reliable accuracy, and wide application. The new modeling procedures use coarse aggregate templates from an aggregate database to improve simulation accuracy and use geometry information from the random generation method to create virtual specimens. The hexagonal close-packed (HCP) structure, which has advantages in simulating shear failure and Poisson's ratio, was employed instead of the SCC structure. The corresponding mechanical calculation for contact micro-parameters was then derived and verified through simple stiffness/bond tests and complete indirect tensile (IDT) tests of a set of asphalt mixture specimens. The results showed that (1) a new set of modeling procedures using the hexagonal close-packed (HCP) structure was proposed and was proved to be effective, (2) micro-parameters of the DEM models were transit form material macro-parameters based on a set of equations that were derived based on basic configuration and mechanism of discrete element theories, and (3) that the results from IDT tests prove that the new approach to determining model micro-parameters based on mechanical calculation is reliable. This new approach may enable a wider and deeper application of the HCP structure DEM models in the research of granular material.
广泛使用的简单立方中心(SCC)模型结构在处理斜向荷载和精确表示泊松比方面存在局限性。因此,本研究的目的是开发一套用于粒料离散元模型(DEM)的建模程序,该程序具有高效率、低成本、可靠精度和广泛适用性。新的建模程序使用集料数据库中的粗集料模板来提高模拟精度,并利用随机生成方法的几何信息来创建虚拟试件。采用在模拟剪切破坏和泊松比方面具有优势的六方密堆积(HCP)结构取代SCC结构。然后通过一组沥青混合料试件的简单刚度/粘结试验和完整间接拉伸(IDT)试验,推导并验证了接触微观参数的相应力学计算方法。结果表明:(1)提出了一套采用六方密堆积(HCP)结构的新建模程序,并证明其有效;(2)基于离散元理论的基本构型和机理推导的一组方程,将DEM模型的微观参数从材料宏观参数转换而来;(3)IDT试验结果证明了基于力学计算确定模型微观参数的新方法是可靠的。这种新方法可能使HCP结构DEM模型在粒料研究中得到更广泛和深入的应用。