香玲核桃青皮破裂力学特性试验研究Cracking mechanical properties of Xiangling walnut green peel

Autor: 陈秀文1,2,李文彬1,2,白效鹏1,2,徐道春1,2 CHEN Xiuwen1,2, LI Wenbin1,2, BAI Xiaopeng1,2, XU Daochun1
Jazyk: English<br />Chinese
Rok vydání: 2023
Předmět:
Zdroj: Zhongguo youzhi, Vol 48, Iss 11, Pp 135-140 (2023)
Druh dokumentu: article
ISSN: 1003-7969
DOI: 10.19902/j.cnki.zgyz.1003-7969.220446
Popis: 为了给青核桃脱皮装备的设计提供理论依据并完善脱皮工艺,对香玲青核桃的几何特征进行测定,并利用微机控制电子万能试验机对其进行不同条件下的单因素力学特性试验。以青皮破裂力和破裂功耗为评价指标,分析了加载方向、加载速率、青核桃外形尺寸、刀片划割处理、阴凉放置处理及青皮含水率对青皮破裂的影响,并拟合了青核桃受压过程中压力随位移的变化曲线。结果表明:香玲青核桃平均球度为0.94,不同部位处青皮厚度不同,青核桃可以简化成非均匀外壳的球体;青皮受压破裂时裂纹只有1条且沿挤压方向延伸出现;青皮破裂受加载方向和外形尺寸的影响,沿纵径方向挤压时青皮更易破裂,青核桃尺寸等级越大,青皮越不易破裂;加载速率对青皮破裂力和破裂功耗的影响不显著;通过烘干降低青皮含水率会影响青皮破裂力和破裂功耗的大小;将青核桃在室内阴凉放置60 h或使用刀片划割后进行加载,青皮更易破裂。因此,为了更好地脱青皮,可以采取对青皮核桃进行分级、刀片划割青皮表面、阴凉放置等措施。In order to provide theoretical basis for the design of green walnut peeling equipment and improve the peeling process, the geometric characteristics of Xiangling green walnut were determined, and the single factor mechanical property tests were carried out under different conditions by microcomputer controlled electronic universal testing machine. The effects of loading direction, loading rate, overall dimension, blade cutting treatment, shade placement theatment and green peel moisture content were analyzed by using the cracking force and power consumption as evaluation indexes, and the curve of force changing with displacement during the loading process of green walnut was fitted. The results showed that the average sphericity of Xiangling green walnut was 0.94, and the thickness of green peel at different parts was not uniform, and the green walnut could be simplified as a sphere with non-uniform shell. There was only one crack in the green peel under compression and it appeared along the extrusion direction. The grean peel cracking was affected by the loading direction and overall dimension. The green peel was easy to crack by extrusion along the longitudinal diameter. The larger the size grade of green walnut, the more difficult to break the peel. The effect of loading rates on the cracking force and power consumption of green peel was not significant. Reducing the moisture content of green peel by drying could affect the cracking force and power consumption of green peel. If the green walnut was squeezed after placing indoors in the shade for 60 h or being cut with a blade, the green peel was obviously easier to crack. In order to better remove the peel of green walunt, measures can be taken such as grading, cutting the surface of green walnut with blades, placing in shade and so on.
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