稻米籽粒静态力学特性的表征与分析

    CHARACTERIZATION AND ANALYSIS OF STATIC MECHANICAL PROPERTIES OF RICE

    • 摘要: 为了解析制米过程中稻米籽粒力学特性的变化,以10种粳稻和10种籼稻为原料,采用物性测定仪分别测定稻谷、糙米和精米的压缩、剪切及三点弯曲力学特性,并对它们的压弯剪力学特性进行了比较分析。结果表明:稻谷籽粒受压缩载荷时,内部糙米首先断裂,故其压缩力-时间特征曲线上出现尖峰;在剪切载荷和三点弯曲载荷作用下,稻谷、糙米、精米3种籽粒的断裂均源于内部裂纹的产生;粳稻谷壳和糙米皮层的存在弱化了粳稻品种间压缩力的差异,籼稻谷壳的存在弱化了籼稻品种间压缩力的差异,粳稻的谷壳对于品种间剪切破碎力差异的影响大于皮层,籼稻糙米皮层的保护作用对于品种间剪切破碎力的影响大于稻壳,稻谷谷壳的存在弱化了粳稻和籼稻品种间三点弯曲破碎力的差异;粳稻和籼稻3种籽粒的压弯剪力学特性均为压缩力 >剪切破碎力 >三点弯曲破碎力,压缩能 >剪切破碎能 >三点弯曲破碎能。

       

      Abstract: In order to explore the mechanical properties of rice,the compressing force (CF),shear fracture force (SFF) and three point bending force (TPBF) mechanical characteristics of rough-rice,brown-rice and milled rice were tested and analyzed by using texture analyzer with 10 kinds of japonica and indica paddy as raw material.The results showed that the force-time curve of rough rice kernel under compressive loading had a peak before the kernel was completely broken,because the brown-rice was broken first.Under the three-point and shearing loading,the break of these three kernels were all originated from the internal creaks.The existence of husk and bran of japonica paddy weakened the CF difference of rice varieties,while the husk of indica paddy weakened the CF difference of rice varieties.The husk of japonica paddy had a greater influence on weakening the SFF difference of rice varieties than the bran.The bran of indica paddy had a greater influence on weakening the SFF difference of rice varieties than the husk.The husks of the two paddies both weaken the TPBF difference of rice varieties.The compressive and shear properties of japonica and indica paddy were all in the sequence of compression force >shear fracture force >three-point bending force,and compression energy >shear fracture energy >three-point bending energy.

       

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