旋耕入土部件有限元仿真研究与关键参数优化

Finite Element Simulation Research and Key Parameter Optimization of Rotary Plowing Parts

针对旋耕入土部件易受到较大的冲击和载荷,存在结构弯曲变形和切削功耗大等问题,基于Ansys Workbench对旋耕入土部件进行静力学、模态与疲劳仿真分析,并通过LS-DYNA中SPH无网格法模拟旋耕刀具切削土壤的动力学过程。设计正交仿真试验,通过响应面法对其关键设计参数进行优化,降低切削功耗,为旋耕刀具的进一步试验研究提供依据。研究结果表明:旋耕刀最大位移变形值为1.2133mm,发生在正切刃处;最大应力值为181.52MPa,发生在背缘曲线与刀柄连接处;最小疲劳寿命位置与最大应力位置相近;模态分析中前6阶的固有频率为133.77~1824.1Hz,第5阶模态振幅达到最大198.37mm,变形严重。SPH法切削土壤过程得到能量、切削阻力等变化规律,并通过正交仿真试验和响应面法求解最优参数组合,弯折点包角30°、侧切刃弯折线方向角51°和弯折角120°,此时最小功耗为0.181kW。

In view of the fact that the rotary plowing parts are susceptible to greater impact and load,there are problems of structural bending and deformation and large cutting power consumption.This paper is based on Ansys Workbench software to carry out static analysis,modal and fatigue analysis of the rotary tillage single cutter,and uses the SPH method in LS-DYNA to simulate the dynamic process of the rotary tillage tool cutting the soil,and design the orthogonal rotation combined simulation test,using cutting power consumption as an indicator,optimize its key design parameters,and provide a basis for further experimental research of rotary tillage tools.The results show that the maximum deformation value of the rotary tiller is 1.2133mm,which occurs at the tangent edge;the maximum stress is 181.52MPa,which occurs on the inside of the tool and the curved part of the blade;The natural frequency of the first 6 orders is 133.77-1824.1Hz,and the amplitude of the fifth mode reaches the maximum of 198.37mm,and the deformation is serious;the SPH method cuts the soil to obtain the change law of energy and cutting resistance,and passes orthogonal simulation test and response surface method.The optimal parameter combination is the bending point wrap angle is 30°,the alpha angle is 51°and the bending angle is 120°,and the minimum power consumption is 0.181kW.