多孔沥青混合料粘弹塑性损伤模型

为合理描述多孔沥青混合料在中低温度外界荷载作用下的力学特性,基于增量型本构方程,采用Weibull损伤函数、广义Maxwell粘弹模型与D-P塑性模型,构建了粘弹塑性损伤模型．以此模型为分析手段,对不同温度和加载速率下的单轴压缩应力-应变曲线进行拟合,并分析温度与加载速率对模型参数的影响规律．分析结果表明:多孔沥青混合料粘弹参数随着温度的降低逐步退化成弹性参数,塑性模型中的体积模量和剪切模量也随温度呈现出明显的粘弹特性,塑性应变产生时对应的应变值与损伤应变阙值基本保持一致,温度及加载速率对于混合料的损伤扩展也有显著影响．构建的理论模型可以有效表征多孔沥青混合料在常温和低温下受荷时的力学损伤特性．

Viscoelastic-plastic damage model of porous asphalt mixtures

To characterize the mechanical behaviors of porous asphalt mixtures under loading at normal and low temperatures, a viscoelastic-plastic damage model, which includes Weibull damage function, Generalized Maxwell and Drucker-Prager model, was presented based on incremental constitutive equation. Experimental data from uniaxial compressive strength tests conducted at different strain rate and different temperature were used to validate the efficacy of the model, and the change rules of model parameters in different temperatures and loading rates were investigated. The test and analysis results show that parameters in viscoelastic model begin to behave like the elastic materials. The volume modulus and shear modulus also show obvious viscoelastic properties along with the changes of temperature and load rate. Additionally the strain plastic strain initializes keep almost same to the critical damage strain, which accommodate to the presented hypothesis. The damage curves of porous asphalt mixtures can also reveal the effects of different temperature and load rate. This model can successfully characterize the damage and mechanical behaviors of porous asphalt mixtures at normal and low temperatures.