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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.
In order to reasonably describe the mechanical behavior of porous asphalt mixture under moderate and low temperature external loads, a viscoelasto-plastic damage model is constructed based on incremental constitutive equation with Weibull damage function, generalized Maxwell viscoelastic model and DP plastic model. Based on this model, the uniaxial compressive stress-strain curves at different temperatures and loading rates were fitted and the influence laws of temperature and loading rate on the model parameters were analyzed.The analysis results showed that the viscoelastic parameters of porous asphalt mixture As temperature gradually degenerates into elastic parameters, the bulk modulus and shear modulus in the plastic model also show obvious viscoelastic properties with temperature, and the corresponding strain and plastic strain thresholds at the time of plastic strain are basically the same , Temperature and loading rate also have a significant impact on the damage propagation of the mixture.The theoretical model can effectively characterize the mechanical damage characteristics of porous asphalt mixture under normal temperature and low temperature.