分别使用有限元和离散元数值方法模拟沙柳颗粒的压缩成型过程,并通过分析沙柳颗粒压制初期、中期、中后期、结束4个时刻的宏细观力学特性来揭示其成型机制。研究表明：宏观上,物料柱应力由零逐渐增大,且应力由开始集中在上表面,再到上半部分,最后整个物料柱应力均匀分布;细观上,颗粒分布由松散到密集,法向和切向接触力分布由初期的杂乱无章到形成菱形,再到大环状,最后到小三角形稳定结构,颗粒速度场经历竖直向下、形成分隔带,分隔带下移,直至消失。
Abstract
The compression molding process of salix psammophila granules was simulated based on finite element and discrete element numerical methods. Furthermore, the forming mechanism of salix psammophila granules was revealed by analyzing the macro and meso mechanical properties at the initial, middle, middle, late and the end stages. The results show that macroscopically the stress of the material column increases gradually from zero, and in the beginning the stress concentrates on the upper surface, then gradually spreads to the upper part, and finally the stress of the whole material column is evenly distributed; Microscopically, the particle distribution changes from loose to dense, the distribution of normal and tangential contact forces changes form the initial disorder to the formation of rhomboid, and then to the large ring, and finally to the small triangular stable structure. The particle velocity field goes straight down and forms a separation zone, which moves down until it disappears.
关键词
生物质 /
沙柳颗粒 /
致密成型 /
离散元 /
有限元
Key words
biomass /
salix psammophila granules /
compact forming /
discrete element /
finite element
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基金
国家自然科学基金（51665045）; 内蒙古自然科学基金（2021LHMS05004; 2020LH05020）
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