散体道床的非线性力学特性研究

Research of Nonlinear Mechanical Properity for Granular Ballast bed

目前,国内外学者采用有限元或多体动力学能较好地研究桥上有砟轨道动力特性,但是在对道床结构进行建模时,往往采用线弹性属性,忽略了其作为散体材料的非线性特性,不能真实反映出散体道床的力学特性,由此也会一定程度影响研究成果的准确性。本文基于离散单元法对散体道床开展动三轴试验的数值计算,根据其受力变形特点,提出了适用于散体道床的非线性力学本构模型Eσ=31.1σ0.35,为有限元或多体动力学研究中散体道床非线性特性参数取值提供思路和参考。

Researchers tend to use finite element method or multi-body dynamics for studying the dynamic characteristics of ballast track on bridge at present.However,researches set granular ballast bed which has a high degree of nonlinear characteristics assimplified linear elastic material which leads truly influence on its mechanical characteristics because of ignoring its granular properties.Therefore,the paper carried out the numerical simulation of dynamic triaxial test of granular ballast bedbased on the discrete element method and put forward the nonlinear mechanical constitutive modelEσ=31.1σ0.35 which is suitable for granular ballast bed in finite element method or multi-body dynamics.