【摘要】 以艾草茎秆为研究对象，利用EDEM仿真软件，分别基于Hertz—Mindlin、Hertz—Mindlin with bonding V2模型建立艾草茎秆刚性、柔性离散元模型。通过单轴压缩试验确定艾草茎秆的泊松比、弹性模量、剪切模量分别为0.33、91.37 MPa、34.35 MPa。以休止角和弯曲破坏力为响应指标，通过Placktt—Burman试验、最陡爬坡试验和Box—Behnken响应面试验对艾草茎秆的接触参数和黏结参数进行标定。结果表明：艾草茎秆与钢板的碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.4、0.47、0.2。艾草茎秆之间的碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.3、0.49、0.14。艾草茎秆黏结模型中单位面积法向刚度为5.51×10¹² N/m³,单位面积切向刚度为8.40×10¹¹ N/m³,临界法向应力为20.69 MPa,临界切向应力为20.57 MPa,黏结半径为0.62 mm。采用休止角试验和弯曲试验对标定的参数进行验证，休止角和弯曲破坏力的物理试验均值与仿真试验均值相对误差分别为0.43%、2.10%,为艾草茎秆离散元仿真模型建立和收割机械的设计优化提供参考。更多还原

【Abstract】 Based on the Hertz—Mindlin and Hertz—Mindlin with bonding V2 models, rigid and flexible discrete element models of wormwood stems were developed using EDEM simulation software. Uniaxial compression tests determined the Poisson’s ratio, elastic modulus, and shear modulus of wormwood stems to be 0.33, 91.37 MPa and 34.35 MPa, respectively. To calibrate the contact and bonding parameters of wormwood stems, the Placktt—Burman test, steepest ascent test, and Box—Behnken response surface test were conducted, using the angle of rest and bending failure force as response indicators. The results showed that the collision recovery coefficient, static friction coefficient, and rolling friction coefficient between wormwood stems and harvesting equipment were 0.4, 0.47 and 0.2, respectively, while those among wormwood stems were 0.3, 0.49 and 0.14, respectively. In the bonding model of wormwood stems, the normal stiffness per unit area was 5.51×10¹² N/m³, the tangential stiffness per unit area was 8.40×10¹¹ N/m³, the normal critical stress was 20.69 MPa, the tangential critical stress was 20.57 MPa, and the bonding radius was 0.62 mm. The calibrated parameters were validated through angle of rest and bending failure tests, with relative errors between physical and simulation test mean values of 0.43% and 2.10%, respectively. These findings provide a valuable reference for the development of discrete element simulation models for wormwood stems and the optimization of harvesting machinery design.更多还原