车轮荷载下土壤静力学特性分析

摘要

利用有限元软件ANSYS建立三维有限元模型，模拟车轮和土壤的静态接触，进行非线性有限元分析，研究车轮荷载下土壤的静力学特性。采用基于Drucker-Prager的弹塑性模型来模拟真实土壤，并考虑摩擦作用。分别采用刚性轮模型和超弹性轮胎模型模拟车轮，并将2种情况进行对比。结果表明：在车轮荷载作用下，土壤的竖向位移和等效应力在轮胎与土壤接触的区域最大；土壤的竖向位移和等效应力随土壤深度的增加而减小；土体在刚性轮作用下的变形和应力要远大于其在超弹性轮作用下的值，表明虽然刚性轮几何形状简单，模型设置容易，但是与超弹性轮胎模型相比，这种模拟精确度低。%This paper establishes a 3 D finite element model by means of definite element software ANSYS to simulate static contact between wheels and soil and carries out nonlinear finite element analysis to study statics characteristics of soil under wheel load. The paper simulates true soil by means of elastic-plastic model based on Drucker-Prager and considers friction effect. The paper simulates wheels by adopting rigid tyre model and super-elastic tyre model, respectively, and compares two cases. The results show that the vertical displacement and equivalent stress in the contact area between tyres and soil are the maximum under the wheel load; and decrease with increase of soil depth; the deformation and stress of soil mass under the effect of rigid tyres are much larger than those under the effect of super-elastic tyres, showing that the accuracy of simulation with rigid tyres is low in comparison with super-elastic tyre model regardless of its simple geometry and easy setup of model.