花生脱壳力学特性的实验研究

Mechanical Characteristics of Peanut Cracking

利用微机控制的电子拉压实验机对川西地区花生进行施压的力学实验。并以花生破损力为目标参数,以施压方向、施压速率、含水率为因素进行三因素三水平有重复观测值的正交试验。结果表明:花生壳厚沿不同部位均匀分布;花生在被压缩时,均会经过弹性变形、塑性变形和突然破裂3个阶段;花生施压方向、施压速率、花生含水率对花生破损力都有极显著影响,并得到不同方向在弹性范围内的花生壳压缩与变形的回归方程,提出花生脱壳的最佳参数组合为花生施压力方向为顶面(x向)、施压速率为30mm/min、含水率15.8%。

To improve cracking quality of peanuts from the western part of Sichuan province, mechanical characteristics of peanut cracking were investigated using a computer-controlled electronic tension and compression machine. A 9-run, 3-level orthogonal array design was employed to examine the effects of pressure location, loading rate and water content on peanut breaking force. The results indicated that the thickness of peanut shell was evenly distributed in different parts of peanuts. During the compression of peanut shell, three stages, i.e., elastic deformation, plastic deformation and sudden rupture occurred. The above factors significantly affected the breaking force of peanut shell. Regression equations of loading force with respect to degree of deformation of peanut shell under different compression directions were obtained through force analysis and the optimal values of the above factors for peanut cracking were determined as follows： pressure location, top surface （along the x- axis）; loading rate, 30 mm/min; and water content, 15.8%.