基于离散元的柔性作物茎秆振动响应仿真  

Simulation of Vibration Response of Flexible Crop Stem Based on Discrete Element Method

作　　者：王奇瑞[1] 毛罕平[1,2] 李青林 WANG Qirui;MAO Hanping;LI Qinglin(Key Laboratory of Modern Agricultural Equipment and Technology,Ministry of Education,Jiangsu University,Zhenjiang 212013,China;High-tech Key Laboratory of Agricultural Equipment and Intelligentization of Jiangsu Province,Zhenjiang 212013,China)

机构地区：[1]江苏大学现代农业装备与技术教育部重点实验室,镇江212013 [2]江苏省农业装备与智能化高技术研究重点实验室,镇江212013

出　　处：《农业机械学报》2020年第11期131-137,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2017YFD0700100)。

摘　　要：建立考虑柔性作物茎秆振动响应特性的动力学模型,对探索谷草分离机理、分析谷物分离过程和联合收获机参数优化具有重要意义。本文提出考虑柔性作物茎秆振动响应特性的动力学仿真模型,研究了作物茎秆的动力学响应特性。首先,给出了作物柔性茎秆的动力学模型和动力仿真方法;以成熟期小麦第3节间为例,测量了茎秆的内外径、单位质量密度和弹性模量等参数;对茎秆的横向弯曲振动和纵向拉伸振动进行仿真,研究茎秆的动力学响应特性,并与理论计算结果进行比较。通过仿真获得长度108 mm、外径3.7 mm、内径1.9 mm、弹性模量5.27 GPa的小麦茎秆的横向振动频率和纵向振动频率分别为164.28、7633.59 Hz,与理论计算结果的相对误差分别为0.28%和0.12%。最后,通过谷草分离仿真实验,验证了柔性作物茎秆模型的实用性。In the field of harvesting machinery,it is advantageous to consider the characteristics of crops in the design stage rather than through actual mechanical tests especially in terms of reducing costs and shortening the development cycle.By establishing a dynamic model that considered the vibration response characteristics of flexible crop stems,it was of great significance to explore the separation mechanism of grains and grass,analyze the grains separation process and optimize the parameters of the combine harvester.A dynamic simulation method for flexible crop stem was proposed,and the dynamic response characteristics of crop stem were studied.Firstly,the dynamic model and dynamic simulation method of crop flexible stem were given.Taking the third internode of the mature wheat as an example,important parameters such as the inner and outer diameter,unit mass density and elastic modulus of the stem were measured.Then,by simulating the lateral and longitudinal vibration characteristics of the stem,the basic dynamic response characteristics of the stem were studied,and the reliability of the simulation was verified by comparing with the theoretical calculation results.The lateral vibration frequency and longitudinal vibration frequency of the wheat stems with a length of 108 mm,an outer diameter of 3.7 mm,an inner diameter of 1.9 mm,and a Young's modulus of 5.27 GPa obtained by simulation were 164.28 Hz and 7633.59 Hz,respectively.The relative errors of the theoretical calculation results were 0.28%and 0.12%,respectively.Finally,the practicability of the flexible stem model was verified by simulating the separation experiment.The simulation results were in good agreement with the theoretical calculation results.

关 键 词：作物茎秆 离散元 柔性 振动 

分 类 号：S225.3[农业科学—农业机械化工程]