基于有限元方法的平房仓中小麦堆的密度分布研究

Density Distribution of Wheat Pile in a Flat Warehouse on Finite Element Method

选定剑桥修正模型作为小麦堆的应力与应变关系本构方程,使用有限元方法计算平房仓中小麦堆的应变分布值,由应变值计算出平房仓中小麦堆的密度分布值。结果表明:小麦储藏在平房仓中,其堆密度分布是不均匀的。在同一含水率下,小麦平均层密度随着粮层深度的增加而增加,增加率随粮层深度的增加而减小;在同一粮层下,小麦的堆密度随距仓壁的距离减小而减小,在粮仓的拐角处小麦堆密度达到该层的最小值,在该层的中间位置密度到达最大值,当粮层深度越深,小麦堆层密度分布越不均匀;平房仓内小麦的平均堆密度随着含水率的增加而减小,平均堆密度相对于无压缩密度的增加率随含水率增加而增大;由剑桥修正模型计算出的数据拟合了平房仓中小麦平均层密度与粮层深度、含水率之间的关系方程。实仓验证得到:该模型计算的平房仓中小麦的质量与实仓内账面小麦质量的误差小于1.64%。

The Modified Cambridge model was selected as the constitutive equation of stress-strain relationship of a wheat heap.The strain distribution value of the wheat heap in a flat warehouse was calculated by finite element method,and the density distribution value of the wheat heap in the flat warehouse was calculated by the strain value.The results indicated that the density distribution of the wheat heap in the flat warehouse was uneven;the average density of the wheat layer increased with the increase of wheat layer depth and the increasing rate of density of the wheat layer decreased with the increase of the wheat layer depth at the same moisture content;the density of wheat decreased with the decrease of distance from the wall of the flat warehouse,and the density of wheat heap reached the minimum value of the layer at the corner of the flat warehouse,but the density reached the maximum at the middle position of the layer;the deeper the wheat layer was,the more uneven the density distribution of the wheat layer was;the average density of wheat heap in the flat warehouse decreased with the increase of moisture content,and the increasing rate of the average heap density relative to the uncompressed density increased with the increase of moisture content.The relationship equation between an average layer density of wheat heap and the layer depth,and the moisture content in the flat warehouse was fitted by the data calculated from the Modified Cambridge model.The verification results indicated that the error between the weight of wheat calculated by this model and the book weight of wheat in the bungalow was less than 1.64%.