基于ALE有限元仿真的土壤切削振动减阻

    Numerical simulation on resistance reduction of soil vibratory tillage using ALE equation

    • 摘要: 针对浙江省茶园土壤压实问题造成小型茶园作业机功率不足问题,提出了茶园振动深松的土壤作业方法。以浙江龙井茶园压实土壤为分析对象,针对土壤深耕铲-土壤切削过程的动力学数值仿真,建立了土壤静态切削力学模型,并进行了土壤大变形切削的屈服失效分析。采用ALE算法模拟了土壤静态切削中深耕铲的切削阻力变化情况,建立了深耕铲-土壤的三维有限元模型并分析了振动切削的振动类型、频率、振幅以及深耕铲的前进速度对土壤切削阻力降低的关系,得出了振动频率和振幅对切削力的影响规律。进一步研究了不同的振动切削条件下,振动类型和刀具的切削速度对切削阻力的影响,通过合理选取一定的深松铲外加振动激励的振幅和频率能够得到最小的切削阻力,实例分析证明,振动频率取为25?Hz,振幅为14?mm时,振动切削的插入阻力能达到最小,切削阻力能降低约22%。上述研究结果为土壤振动切削减阻的外加振源参数优化提供了设计依据。

       

      Abstract: A method of soil vibration cutting resistance reduction was proposed for deep-loosing. Example for the compression soil of Zhejiang Longjing tea garden, a soil static cutting mechanics model and soil-cutting yield failure mode were studied in this paper. According to the interaction process of deep shovel-soil, the static cutting resistance changes of deep shovel was analyzed by 3D finite element model with algorithm of ALE. Furthermore, the influences of soil-cutting resistance on the vibration source type, the vibration frequency and vibration amplitude were also studied. As an example of a compaction soil in tea garden, the influences of soil resistance reduction with difference vibration cutting conditions was studied. It showed that the soil resistance reduced with the vibration frequency and amplitude increased, and soil cutting resistance was up to minimum. Case analysis?showed that with the vibration?frequency of?25?Hz, and the amplitude of 14 mm, the soil cutting resistance could be reduced by 22%. So, above-mentioned studies provided a design basis of soil cutting resistance reduction with vibration exciting, and parameter optimization of tillage impressed vibration source.

       

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