中文摘要：

依据筛面、稻谷籽粒和短茎秆的实物结构与材料特性建立了分析模型，基于离散元法（DEM）模拟和分析谷物筛分过程；研究了基于并联机构振动筛的8种组合运动形式对谷物筛分的影响规律；综合考虑了筛分效率与时间的关系及清洁率对筛分效果的影响，提出了筛分效果的评定方法；应用该评定方法来分析三维运动筛面的筛分效果，所得结论为多维振动筛面运动形式的选择提供了参照。

英文摘要：

According to the physical structure and material properties ot screen surtace, rice grain and short stalk, an analytical model was established. Based on DEM, the process of grain screening was simulatied and analysed. Then the influences of eight kinds of combined motion form on grain screen- ing was studied based on parallel mechanism of vibrating screen. In comprehensive consideration of the cleaning and the relationship between screening efficiency and time, the evaluation methods of screen- ing effect was put forward. By using the evaluation method, the screening effect of the three dimen- sional motion screen was analyzed. The conclusion provides reference for the choice of multidimension- al vibrating screen.