不同温度和应变率下水工沥青混凝土细观能量演化研究

Meso Energy Evolution of Hydraulic Asphalt Concrete Under Different Temperatures and Strain Rates

为揭示水工沥青混凝土在不同温度和应变率下的细观能量演化规律,基于离散元颗粒流程序(PFC3D),根据试件中骨料级配建立三维细观随机骨料模型,利用该模型对不同温度范围应变率条件下的水工沥青混凝土单轴受压试验进行离散元研究。分析水工沥青混凝土破坏全过程中细观能量演化特征,探讨温度和应变率对应变能和耗散能演化特征的影响,从细观层次研究能量演化的机制。研究结果表明,在破坏过程中粘结应变能和线性应变能随变形增大而增大,摩擦耗散能和阻尼耗散能随变形增大而增大;应变率为10-4s-1时,温度从10℃降低至-20℃,应变能储能极限提高11.46倍,能量耗散量提高6.37倍,温度为0℃时,应变率从10-5s-1提高至10-2s-1,应变能储能极限提高6.37倍,能量耗散量提高3.71倍,应变能和耗散能随温度降低和应变率提高而增大。

In order to reveal the energy evolution law of hydraulic asphalt concrete under different temperatures and strain rates,based on the discrete element particle flow code(PFC3 D),a three-dimensional meso random aggregate model was established according to the aggregate gradation in the specimen.The discrete element method was used to study the uniaxial compression test of hydraulic asphalt concrete in different temperature range and the strain rate.This paper analyzes the meso energy evolution characteristics of hydraulic asphalt concrete in the whole failure process,discusses the influence of temperature and strain rate on the evolution characteristics of variable energy and dissipation energy,and studies the energy evolution mechanism from the meso level.The results show that the bond strain energy and linear strain energy increase with the increase of deformation,the friction dissipation energy and damping dissipation energy increase with the increase of deformation;When the strain rate is 10-4 s-1,the temperature decreases from 10℃to-20℃,the strain energy storage limit increases by 11.46 times,and the energy dissipation increases by 6.37 times;The strain rate increases from 10-5 s-1 to 10-2 s-1 at 0℃,the strain energy storage limit and energy dissipation increase by 6.37 times and 3.71 times,respectively.The strain energy and dissipation energy increase with the decrease of temperature and the increase of strain rate.