土壤旋切振动减阻的有限元分析

提出了一种对旋耕机具施加振动载荷进行压实土壤切削减阻的方法。对板结土壤参数进行土壤三轴测试试验，结合LS—DYNA的MAT147材料模型，测试土壤材料模型参数，并建立了南方丘陵地带板结土壤本构模型及土壤振动旋切过程的有限元数值模型。通过三维数值模拟和计算，分析了外加激励的振型、频率及振幅等因素对土壤切削阻力的影响及变化规律，并得到实现最优减阻效果的各项参数组合。研究结果表明，采用振动旋耕机具进行土壤作业过程中，选择合适振动频率、幅值以及振动类型的外加刀具振动能实现土壤耕作减阻，有效降低机具的土壤切削功率。

Finite Element Simulation and Analysis on Soil Rotary Tillage with External Vibration Excitation

A method of compacted soil rotary tilling with variant frequency vibrationis proposed.The tea garden soil physical parameters was measured with soil triaxial test referring to the MAT147 soil model from LS-DYNA material library,then a soil constitutive model of the southern hills’ harden soils and the finite element numerical simulation model for soil vibratory rotary cutting process were built.Through 3-D numerical simulation and analysis,the influence rules on soil cutting resistance caused by many factors of external vibration excitation such as amplitude,frequency and vibration model were studied,and the optimal vibration operation parameters conducive to soil cutting resistance reducing was deduced and confirmed.The results show that the finite element method SPH is effective for large strain and high strain rate numerical simulation of compacted soil rotary cutting,and choosing appropriate vibration frequency,amplitude and vibration types of vibration excitation can reduce tillage mechanism power and improve working efficiency.