Abstract: In order to study the crushing mechanism of fresh tobacco leaves during the orderly grasping process by a mechanical hand,   the Cunsanpi variety yellow tobacco was taken as the research object, a universal testing machine was used to apply radial and lateral compression loads and shear force on the main vein of fresh tobacco leaves, the corresponding loaddisplacement curves were obtained, and the discrete point variation curves of the maximum crushing force and shear force of the tobacco main vein were fitted by the Origin software. The results showed that the average values of the maximum crushing force of radial and lateral compression of the tobacco main vein was 75.25 N, the average compressive strength was 1.175 MPa, the average compressive elastic modulus was 5.79 MPa, the average values of the maximum radial and lateral shear force was 23.04 N, the average shear strength was 0.295 MPa, and the average shear modulus was 0.56 MPa. Additionally, a comparison between the compression and shear mechanical characteristics of the middle and lower tobacco leaves was made, it was found  that the crushing and shearing of middle leaves required greater force,  which can provide a theoretical basis and design reference for the orderly gripping of tobacco leaves by a mechanical hand.

Key words: fresh tobacco main vein, fracture mechanism, compression test, shear test, mechanical characteristics

摘要： 为研究鲜烟叶在机械手有序抓取过程中的破碎机理，以寸三皮黄烟品种为研究对象，利用万能试验机对新鲜烟叶主脉进行径向、侧向的压缩和剪切力学试验，得到不同作用位置的载荷—位移曲线，并利用Origin软件拟合烟叶主脉最大破碎力和剪切力的离散点变化规律曲线。结果表明，烟叶主脉径向和侧向压缩的最大破碎力均值为75.25 N，抗压强度均值为1.175 MPa，压缩弹性模量均值为5.79 MPa；径向和侧向最大剪切力均值为23.04 N，剪切强度均值为0.295 MPa，剪切模量均值为0.56 MPa。对烟株中部叶和下部叶的压缩和剪切力学特性进行比较，发现中部叶破碎和剪切需要施加更大的力。为机械手有序抓取烟叶提供理论基础和设计依据。

关键词: 鲜烟叶主脉, 破碎机理, 压缩试验, 剪切试验, 力学特性