履带-轮-地面相互接触非线性有限元建模
Nonlinear Finite Element Modeling of Track-wheel-ground Contact

为有效预测车辆履带系统动力学响应,应用非线性有限元描述了履带、地面及负重轮之间的接触,并建立了数学模型。在增量方程的基础上采用有限单元法解决了接触边界值问题,在半圆形和等腰梯形两种路面,干沙、粘土和沙壤土3种土壤及不同负重轮位置和履带刚度条件下进行了算例分析。结果表明:车辆在等腰梯形和半圆形路面行驶时,两个边角接地压力最大;路面越软,履带接地压力越小,且越均匀;负重轮间距和沉陷量越小,履带最大接地压力越大;履带张力和负重轮上反作用力随着履带刚度的增加而增大。建立的数学模型能够合理预测履带张力变化、几何大变形和履带接地压力。
In order to effectively predict the dynamics response of the track system of a track vehicle, the contacts between track, ground and wheel were described by using the nonlinear finite element method. The mathematical model was established and the contact boundary values were solved using the finite element method and the incremental equation. When the section shape of ground is semicircular and isosceles trapezoid and the soil type is dry sand, clay and silt loam, the wheel's location and track stiffness are different. Some examples were analyzed. It is concluded that the ground contact pressure at two corners is maximum when the track vehicle is on isosceles trapezoid and semicircular road; when the ground is soft, the ground pressure of the track is smaller and more uniform; when the distance between wheels and its sinkage is smaller, the maximum ground contact pressure of the track is greater; when the track stiffness is larger, track tension and the reaction force on the wheel increase gradually. The model thus established can reasonably predict the variation of tension force, geometric deformation and ground contact pressure of the track