考虑CA砂浆黏弹特征的板式无砟轨道动力响应分析
Dynamic response analysis of slab ballastless track considering viscoelastic characteristics of CA mortar

水泥乳化沥青砂浆是一种典型的黏弹性材料，通过对其蠕变实验数据的黏弹性方程拟合及Prony级数转化，研究CA砂浆材料黏弹性的有限元实现方法，并进一步探究动荷载作用下考虑CA砂浆层黏弹性属性时，板式无砟轨道结构的受力及变形响应特征。研究结果表明：修正的Burgers模型及其转化的Prony级数表达式可以很好地表征水泥乳化沥青砂浆常温时的黏弹特征；在CRTSⅠ型板式无砟轨道结构动力分析中，考虑5 s的动荷载作用时，CA砂浆层定义为黏弹性材料与弹性材料相比，CA砂浆层应力幅值变化较大，最大达到56%左右，轨道板和底座板的力学响应也发生了改变，在结构分析中考虑CA砂浆的黏弹性是必要的。
Cement emulsified asphalt mortar is a kind of typical viscoelastic materials, in this paper, the viscoelastic finite element method of CA mortar material is studied by the viscoelasticity equation fitting and the Prony series transformation of the creep test data, and further to explore under the action of dynamic load, considering the viscoelastic properties of CA mortar layer, the stress and deformation response characteristics of slab ballastless track structure are studied. The results show that: The modified Burgers model and its transformed Prony series expression can well describe the viscoelastic characteristics of cement emulsified asphalt mortar at normal temperature; In the CRTS Ⅰ dynamic analysis of ballastless track structure, considering the 5 s dynamic loading, CA mortar layer is defined as viscoelastic material. Compared with elastic materials, the stress amplitude of CA mortar layer changes more, the maximum can reach up to about 56%, the mechanical response of the orbital plate and base plate also changed. Considering the viscoelasticity of CA mortar is necessary in the structural analysis