车用空气弹簧有限元分析方法

Finite Element Method to Analyze Vehicle Air Spring

空气悬架系统的刚度直接影响整车性能,而悬架刚度又主要取决于空气弹簧刚度特性。由于在工作行程中橡胶气囊发生多重非线性问题,难以用传统方法预估弹簧刚度。为此,基于空气弹簧结构分析、非线性有限元理论,提出一种空气弹簧力学特性预估方法。在这方法中以Yeoh模型模拟橡胶层,rebar模型代表帘线层,缘板及活塞作为刚体,气体流动与气囊体变形耦合。为了检验该方法的有效性和可行性,以某一大客车悬架用膜式空气弹簧为应用实例,根据结构尺寸用CAD软件UG建立三维实体模型,并用Hypermesh软件划分网格,用试验测试橡胶材料的应力应变关系。将有限元模型导入非线性有限元软件abaqus中进行数值计算。计算结果表明,所提出的方法是切实可行,为汽车悬架用空气弹簧研制开发提供了一种较为经济实用的预估方法。

Air suspension stiffness directly affects performances of vehicle. Suspension stiffness mainly depends on the stiffness of air spring. Traditional methods can hardly predict the stiffness because the rubber air bag generates multiple nonlinear problems during working process. For this, based on the structure analysis and nonlinear finite element theory, a prediction method for the dynamic characteristic of air spring is proposed, in which Yeoh model is used to simulate the rubber layer, rebar model represents cord layer, listrium and piston are used as rigid body, airflow is coupled with air bag deformation..To prove its validity and feasibility, diaphragm air springs for bus suspension are taken as examples. 3-D solid model is built by using CAD software UG on the basis of the structure size. Mesh is also generated by using hypermesh softeware. The relationship between stress and strain of rubber materials is tested. Numerical calculation of the finite element model is carried out by using nonlinear finite element software abaqus. The calculation results show that the finite element method is feasible. It provides an economical and practical prediction method for the development of air springs for vehicle suspension.