冬小麦籽粒受挤压特性的有限元分析及试验验证

    Finite element analysis and experimental verification of wheat grain under compression loads

    • 摘要: 为降低小麦籽粒在收获、贮藏、运输过程中的机械损伤,掌握小麦籽粒粉碎机理,运用有限元法建立小麦籽粒的力学模型,研究小麦籽粒在压缩载荷作用下的应力分布规律。在材料力学万能试验机上进行压缩试验,测得不同含水率9.1%~21.6%的小麦籽粒在3种压缩型式下的弹性模量为98.86~206.59 MPa,屈服强度为0.8~1.95 MPa,破碎负载为63.44~154.77 N,最大应变为0.71%~1.02%。结果表明:在3种压缩型式下,破碎负载、弹性模量、屈服强度随着含水率的增加均有明显下降;在同一含水率下,B型压缩时破碎负载最大,L型压缩时次之,H型压缩时最小;屈服强度和最大变形在采用B型和L型压缩时较大,在H型压缩时较小;其主要破碎形式为在腹沟位置产生裂纹。比较3种压缩型式下的试验值的和仿真值,二者最大差异是12%,验证了仿真数值解可行性。

       

      Abstract: In order to reduce the mechanical damage of wheat grain in the harvest, storing, transporting process and master the comminution mechanism, mechanical model of compressing wheat grain was established by the finite Element Method, and the stress distribution was analyzed. Compression tests had been conducted on wheat grain at different moisture contents by using universal hydraulic test equipment. Three types compression tests results showed that the elastic modulus of wheat grain was 98.86-206.59 MPa, the yield strength was 0.8-1.95 MPa, the failure load are 63.44-154.77 N, the maximum strain was 0.71%-1.02%. The results showed that the failure load, elastic modulus and yield strength were descended obviously with the increase of moisture contents. The failure load of B type was maximum and H was the minimum with the same moisture contents. Meanwhile the elastic modulus and yield strength of B and L were higher than H. The main failure form of wheat grain is the cracks appearing near the ventral groove. The compression test results and Finite Element solutions were compared, which showed that the maximal difference between them was 12%. The simulation numerical solution is confirmed by comparing with the experiment data

       

    /

    返回文章
    返回