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| 大豆静力与动力剪切特性的试验研究 |
| Static and dynamic shear characteristics of soybean |
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| DOI：10.12166/j.zgyz.1003-7969/2020.06.027 |
| 中文关键词: 大豆 直剪试验 循环剪切 剪切刚度 阻尼比 |
| 英文关键词:soybean direct shear test cyclic shear shear stiffness damping ratio |
| 基金项目:河南省高等学校重点科研项目计划(19A560009)；河南省粮油仓储建筑与安全重点实验室开放基金(2016KF-B03)；粮食公益性行业科研专项(201513001) |
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| 中文摘要: |
| 为研究大豆粮堆的静力与动力剪切特性，采用粮食静动直剪仪进行了单调直剪和循环剪切试验。分别探究了不同孔隙率对大豆静力剪切特性的影响、循环剪切过程对大豆动力剪切特性的影响以及不同工况对大豆剪切刚度和阻尼比的影响。结果表明：单调直剪试验中，随着孔隙率的减小，大豆的抗剪强度增加，表现出更为明显的剪胀性，咬合应力和内摩擦角均随孔隙率的减小而增大；大豆在循环剪切过程中发生了剪切硬化现象，单个循环周次均伴随了剪缩和剪胀的交替，随着循环次数的增加相对竖向位移总体表现为增大；大豆剪切刚度的变化范围为7.17~17.92 kPa/mm，阻尼比的变化范围为0.13~0.28；竖向应力的增大导致剪切刚度增大、阻尼比减小；剪切刚度与阻尼比均随循环剪切幅值的增大而增大；初始孔隙率越小，同一循环对应的剪切刚度和阻尼比越大。 |
| 英文摘要: |
| In order to study the static and dynamic shear characteristics of soybean, monotonic direct shear and cyclic shear tests were performed using grain static and dynamic direct shear instruments. The effects of different porosity on the static shear characteristics of soybean, the effects of cyclic shear process on the dynamic shear characteristics of soybean and the effects of different working conditions on the shear stiffness and damping ratio of soybean were investigated. The results showed that the shear strength of soybean increased with the decrease of porosity, and the dilatancy became obvious. The occlusal stress and internal friction angle of soybean increased with the decrease of porosity. In the cyclic shear process, the phenomenon of shear hardening occured in soybean. The single cycle was accompanied by the alternation of shear shrinkage and shear expansion, and the relative vertical displacement increased with the increase of cycle times. The change range of shear stiffness of soybean was 7.17-17.92 kPa/mm, and the change range of damping ratio was 0.13-0.28. The increase of vertical stress resulted in the increase of shear stiffness and the decrease of damping ratio; the shear stiffness and damping ratio increased with the increase of cyclic shear amplitude; the smaller the initial porosity, the larger the shear stiffness and damping ratio corresponding to the same cycle. |
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