关键词: 核桃, 物理特性, 弹性模量, 含水率, 质心

Abstract: In order to improve the deep processing equipment of walnuts and the automatic production efficiency, the basic physical parameters of the three diameter size, water content, friction factor, center of mass and elastic modulus of Yunnan Yangbi walnuts were measured, and quasistatic compression tests were conducted on walnuts with different water contents, and the values of the relevant physical properties of Yangbi walnuts and the mechanical properties associated with them were obtained. The results showed that the overall shape of Yangbi walnuts was short and round, the moisture content of wet walnuts ranged from 22.05% to 31.32%, while the shellbreaking force of walnuts decreased with the decrease of moisture content, the friction coefficient of walnuts in the posture of contact between suture and flat plate on the PVC herringbone surface was 0.53 at the maximum and 0.38 at the minimum on the stainless steel surface, the center of mass of walnuts was measured by the threepoint force measurement method to be biased toward the tip direction, the elastic modulus of wet walnut was roughly 122.03-133.78 MPa, and the elastic modulus showed a trend of decreasing and then increasing with the decrease of moisture content.

Key words: walnut, physical properties, modulus of elasticity, water content, centroid