铁道车辆缓冲器弹性胶泥粘弹性参数的数值反演

研究弹性胶泥的基本物理参数。提出以弹性胶泥简单的静压试验和动力试验反演复杂的三维粘弹性本构参数的数值方法。依据弹性胶泥松弛模量的物理意义,建立三维粘弹性本构模型。依据静压试验的静压力和观测点位移试验数据,建立以弹性有限元为基础的弹性位移反演模型,优化求解该模型可得到泊松比、杨氏模量。根据弹性力学本构关系的基本原理,通过泊松比、杨氏模量可得到粘弹性模型所需要的剪切平衡模量和体积平衡模量。依据动力试验的激振力和观测点位移的时程曲线,建立以粘弹性大变形动力有限元为基础的粘弹性参数反演模型,利用改进的遗传算法对其余和时间相关的粘弹性参数进行优化求解。以重载货车用新型胶泥缓冲器为实例,对弹性胶泥的基本粘弹性参数进行数值反演。反演结果和试验结果吻合较好。

Numerical Inversion of Viscoelasticity Parameter for Elasticity Cement in Draft Gear

The basic physical parameters of the elasticity cement is studied in the paper. On the basis of static and dynamic tests of the elasticity cement used in draft gear, a numerical method of back analysis for (viscoelasticity) parameter of the elasticity cement is proposed. According to the physical meaning of the relaxation modulus, the constitutive equation of viscoelasticity is presented. With the data of static pressure and (displacement) observed in the static test, the elastic finite (element) method is used to get the back analysis for Poisson's ratio and elastic modulus, and then to get the shear balance modulus and the bulk balance modulus according to the basal principle of the elastic mechanics. With the time history data of forces and displacements in the dynamic test, a model of back analysis for viscoelasticity parameters with the viscoelastic dynamic finite (element) method is presented. The improved genetic algorithm is used to find other viscoelasticity parameters (related) with time. An example of heavy haul freight train using new type elasticity cement in draft gear is (presented) to conduct the numerical inversion of the basic viscoelasticity parameters for elasticity cement. The (inversion) results agree well with the test results.