摘要
【目的】砂土作为一种颗粒材料,形状是影响其堆积状态及剪切特性的重要因素,为探究颗粒整体轮廓(球度)对颗粒物理性质的影响。【方法】利用球谐函数随机生成3种复杂形状颗粒和球颗粒模型,通过3D打印技术打印颗粒模型。对4种打印颗粒进行相对密度试验以及直剪试验,分析不同形状颗粒的堆积状态、力学性能。【结果】分析三维颗粒形状指标,发现复杂颗粒的形状差异主要体现整体轮廓方面(球度最大相差0.718,圆度最大相差0.032)。随着球度的增加,颗粒的最大孔隙比从1.843减小到0.803,最小孔隙比从1.121减小到0.603,极限孔隙比差值从0.722减小到0.200,且在相同相对密实度的条件下更容易达到密实的堆积状态;在相对密实度为0.5的条件下,随着颗粒球度从0.241增大到1,试样峰值抗剪强度逐渐减小,内摩擦角从44.6°减小至33.4°,并且内摩擦角和球度存在线性递减关系。【结论】将球谐函数生成不规则颗粒模型的方法与3D打印技术结合可以得到更加贴近真实情况的复杂形状颗粒。基于试验数据得出了复杂颗粒形状指标球度与剪切特性指标的关系式,为实际工程强度设计和数值模拟计算工作中考虑球度影响时提供理论依据。
[Objective]Sand as a kind of granular material,shape is an essential factor affecting its stacking state and shear properties,in order to investigate the influence of the particles′overall contour(sphericity)on the physical properties of the particles.[Methods]Three kinds of complex shape particles and spherical particle models were randomly generated by using the spherical harmonic function,and the particle models were printed by 3D printing technology.Relative density tests and straight shear tests were performed with 4 kinds of printing particles to analyze the stacking state and mechanical properties of particles with different shapes.[Results]Analyzing the 3D particle shape parameters,it was found that the shape differences of complex particles were mainly reflected in the overall contour(the maximum difference of sphericity was 0.718,and the maximum difference of roundness was 0.032).With the increase of sphericity,the maximum porosity ratio of the particles decreased from 1.843 to 0.803,the minimum porosity ratio decreased from 1.121 to 0.603,and the difference of ultimate porosity ratio decreased from 0.722 to 0.200,and it was easier to reach the dense stacking state under the condition of the same relative densities;under the condition of the relative densities at 0.5,with the increase of particle sphericity from 0.241 to 1,the peak shear strength of the specimen decreased gradually,the internal friction angle decreased from 44.6°to 33.4°,and there was a linear decreasing relationship between the internal friction angle and sphericity.[Conclusion]The method of generating irregular particles using the spherical harmonic function is greatly efficient in terms of calculation and storage cost.Based on the present experimental data,the relationship equation between complicated particle shape parameters sphericity and shear property index is derived,which provides theoretical basis for considering the influence of sphericity in practical engineering strength design and numerical simulation calculation work
作者
钟楚珩
王安
陈金辉
周金枝
毛伟琦
幸思佳
ZHONG Chuheng;WANG An;CHEN Jinhui;ZHOU Jinzhi;MAO Weiqi;XING Sijia(School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,Hubei,China;Key Laboratory of Health Intelligent Perception and Ecological Restoration of River and Lake,Ministry of Education,Hubei University of Technology,Wuhan 430068,Hubei,China;China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,Hubei,China;CBMI Construction Co.,Ltd.,Beijing 100176,China)
出处
《水利水电技术（中英文）》
北大核心
2024年第5期38-49,共12页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(52208340)
湖北省高等学校优秀中青年科技创新团队项目(T2022010)
湖北工业大学博士启动基金(BSQD2020051)
武汉市知识创新专项曙光计划项目(2023020201020375)。
关键词
3D打印
颗粒形状
球度
剪切性能
堆积状态
砂土
力学性能
影响因素
3D printing
particle shape
sphericity
shear properties
stacking state
sand
mechanical properties
influence factor
