Granular Matter ( IF 2.4 ) Pub Date : 2023-03-14 , DOI: 10.1007/s10035-022-01302-x Yu Guo, Shichun Chi, Xiaofei Mi, Shihao Yan
Rockfill is a common irregular granular material used in most dam construction projects. The purpose of this paper is to investigate the distribution and size-dependent properties of the mechanical parameters describing the elastic properties and crushing strength of rockfill particles. These statistics can be used as a reference to calibrate the input parameters of numerical models when studying the macroscopic behavior of rockfill with particle breakage using the discrete element method. A series of limestone particles ranging in diameter from 20 to 240 mm were measured in this study using a single particle compression test. The elastic modulus, elastic contact stiffness, tensile stress and fracture force were then determined by characterizing each experimental force–displacement curve. Classical statistical methods were used. It has been shown that Weibull, lognormal and logistic functions can all represent the distributional features of the elastic modulus, tensile stress and fracture force, with the lognormal function being the optimal type here. As the grain size increases, the elastic modulus and tensile stress decrease, while the fracture force rises. Empirical models of power functions effectively reproduced these size-dependent laws. Meanwhile, the relationship between these parameters was also established. Finally, the lognormal function was adopted to express the randomness of the maximum elastic contact stiffness. Some suggestions were made after discussing the positive association between the maximum elastic contact stiffness and grain size. Moreover, the evaluation of the loading strain rates of individual particles tested shows that the present conclusions are applicable to quasi-static case.
Graphical abstract
中文翻译:
堆石料颗粒弹性力学参数及强度指标统计特性试验研究
堆石料是一种常见的不规则颗粒材料,用于大多数水坝建设项目。本文的目的是研究描述堆石颗粒弹性特性和抗碎强度的力学参数的分布和尺寸相关特性。这些统计数据可作为离散元法研究含颗粒破碎堆石料宏观行为时标定数值模型输入参数的参考。本研究使用单颗粒压缩试验测量了一系列直径从 20 到 240 毫米的石灰石颗粒。然后通过表征每个实验力-位移曲线来确定弹性模量、弹性接触刚度、拉伸应力和断裂力。使用了经典的统计方法。已经表明,威布尔函数、对数正态函数和逻辑函数都可以表示弹性模量、拉应力和断裂力的分布特征,这里对数正态函数是最优类型。随着晶粒尺寸的增加,弹性模量和拉应力降低,而断裂力升高。幂函数的经验模型有效地再现了这些依赖于大小的定律。同时,也建立了这些参数之间的关系。最后,采用对数正态函数表示最大弹性接触刚度的随机性。在讨论了最大弹性接触刚度与晶粒尺寸之间的正相关关系后提出了一些建议。而且,