摘要
为避免排种器耐久性试验过程中因排种器振动试验台自身结构限制对排种器性能造成影响,综合运用振动测试、有限元仿真分析和定幅值正弦扫频试验相结合的方法,对新设计开发的排种器振动试验台进行可靠性分析及验证。通过田间振动测试,了解播种机田间作业期间排种器所受地表振动载荷分布情况;通过有限元分析,了解排种器试验台结构固有频率、振型特征及应力分布;通过1~120Hz定幅值正弦扫频试验,对模态分析结果的准确性进行验证。结果表明:排种器试验台1阶约束模态为38Hz,远高于耕作地表振动主激励频率2~12Hz;在垂直方向振动载荷作用下,排种器试验台总成最大Mises应力为24MPa,远低于材料的许用应力。正弦扫频试验结果显示:排种器试验台在36.65、66.38、82.0、102.0Hz附近出现明显振动响应,为结构敏感频段;前4阶约束模态计算结果与正弦扫频试验响应频率差异率均在5%以内,考虑到实际边界约束条件和网格划分所造成的误差,差异在合理范围内,模态分析结果准确可行。综合上述分析,排种器试验台结构稳定可靠,可以开展进一步耐久性试验。本研究有助于排种器设计人员开展排种器振动试验台设计,对后续设计手段和设计流程的提升有积极的作用。
In In order to avoid the influence of the seeder vibration test bench structure on the performance of the seeder during the durability test of the seeder,this paper uses a combination of vibration test,finite element simulation analysis and fixed amplitude sine wave sweep test.Methods The reliability of the newly designed and developed seed meter vibration test bench was analyzed and verified.Through the field vibration test,understand the distribution of ground vibration load on the seeder during field operation;through the finite element analysis,understand the natural frequency,mode shape characteristics and stress distribution of the structure;through the sine wave sweep with a fixed amplitude of 1-120 Hz Frequency test to judge the accuracy of modal analysis results.The results show that the first-order restraint mode of the seeder test bench is 38 Hz,which is much higher than the main excitation frequency of 2-12 Hz for farming surface vibration.Under vertical load,the maximum Mises stress of the seeder test bench assembly is 24 MPa.Far lower than the allowable stress of the material;the frequency sweep test shows that the seed meter test bench has obvious vibration response near 36.65,66.38,82.0,102.0 Hz,which is a structurally sensitive frequency band.The test response frequency difference rates are all within 5%.Considering the actual boundary constraints and the errors caused by the mesh division,the difference results are within a reasonable range,and the modal analysis results are accurate and feasible.Based on the above analysis,the structure of the seed meter test bench is stable and reliable,and further durability tests can be carried out.This article is helpful for the seeder designer to carry out the design of the seeder vibration test bench,and has a certain positive effect on the subsequent design methods and the improvement of the design process.
作者
刘虎
周纪磊
张荣芳
史嵩
位国健
Liu Hu;Zhou Jilei;Zhang Rongfang;Shi Song;Wei Guojian(Shandong Agriculture Machinery Research Institute,Ji’nan 250100,China)
出处
《农机化研究》
北大核心
2021年第8期158-163,共6页
Journal of Agricultural Mechanization Research
基金
国家自然科学基金项目(51605268)
山东省重点研发计划项目(2018GNC112001)
山东省农机装备研发创新计划项目(2018YF022)
山东省农业科学院农业科技创新工程项目(CXGC2018E18)。
关键词
排种器振动试验台
振动测试
模态分析
扫频试验
vibration test bench for seed meter
vibration testing
modal analysis
sweep frequency test
