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水稻籽粒碰撞力學特性研究
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高等學校博士學科點專項科研基金資助項目(20103227120010)、中國博士后科學基金資助項目(20110490124)、江蘇省博士后科研基金資助項目(1102131C)和江蘇高校優(yōu)勢學科建設(shè)工程資助項目(PADP)


Impact Mechanical Characteristics Analysis of Rice Grain
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    摘要:

    根據(jù)水稻籽粒的物理特性建立了橢球體顆粒模型,采用離散元法模擬了籽粒與檢測傳感器碰撞力學過程。結(jié)果表明:對心碰撞時的峰值法向接觸力Fn max隨著曲率半徑的增加而增大,偏心碰撞時籽粒將發(fā)生轉(zhuǎn)動,F(xiàn)n max隨著法向重疊量的減小而減?。籉n max的差異隨著粒徑比γ的增加而增大,當γ=3時峰值力比率η的最小值小于45%。斜碰撞時η的變化呈現(xiàn)出不對稱特性,且η的變化范圍也隨之增大,當γ=3時η的最小值約為30%,接觸力上升時間tr為14~26μs。采用PVDF壓電薄膜作為敏感元件設(shè)計了檢測傳感器,并進行了水稻籽粒沖擊力學試驗。結(jié)果表明,在相同碰撞速度下,輸出電壓峰值在2~4 V范圍內(nèi)波動,接觸力上升時間tr為15~35μs。

    Abstract:

    An ellipsoid particle model was established according to the physical properties of rice grain. The discrete element method was used to simulate the impact process of a grain with a detection sensor. The results indicated that the peak normal contact force Fn max was increased with the increasing of curvature radius during the central impact process. Rotation of grain was driven during the eccentric impact process which reduced the value of Fn max. The differences of Fn max was enlarged with the increasing of grain radius ratio γ, and the minimal value of peak force ratio ηwas lower than 45% with γof 3. The asymmetric variation behavior of ηwas shown during the oblique impact process and the variation range of η was increased. The minimal value of peak force ratio ηwas about 30% with γof 3. The rise time of impact force tr was in the range of 14~26 μs. Then, a detection sensor using piezo-electric polyvinylidene fluoride (PVDF) film as sensitive material was presented and the rice grains impact tests were carried out. The results showed that the peak output voltage was fluctuated in 2~4 V, and the rise time of impact force tr was 15~35 μs. 

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趙湛,李耀明,陳義,梁振偉,劉麗霞.水稻籽粒碰撞力學特性研究[J].農(nóng)業(yè)機械學報,2013,44(6):88-92. Zhao Zhan, Li Yaoming, Chen Yi, Liang Zhenwei, Liu Lixia. Impact Mechanical Characteristics Analysis of Rice Grain[J]. Transactions of the Chinese Society for Agricultural Machinery,2013,44(6):88-92.

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  • 在線發(fā)布日期: 2013-05-28
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