再生沥青混合料单轴静态蠕变试验的离散元仿真

Discrete element simulation on uniaxial static creep test of recycled asphalt mixtures

根据新拌沥青混合料细观力学研究现状,提出了基于三维离散元方法和虚拟图像技术的再生沥青混合料细观力学仿真思路,并介绍了实现过程.利用虚拟图像技术,生成基于再生沥青混合料细观结构的虚拟试件,建立了离散元细观模型,提出了细观模型参数的确定方法.利用再生沥青胶浆单轴静态蠕变试验,获得了再生沥青胶浆的细观模型参数.依据时温等效原理,进行了粘弹性参数转换,以提高模型的计算效率.采用PFC3D离散元方法,利用PFC自带的FISH语言,编制相应的程序,输入转换后得到的模型参数.使用模型参数模拟再生沥青混合料单轴静态蠕变的虚拟试验,并与再生沥青混合料室内试验结果进行对比,验证了虚拟试验的合理有效性.

According to the micromechanics status quo of fresh asphalt mixtures,a simu- lation thought of recycled asphalt mixture micromechanics is proposed based on three- dimensional discrete element method and the virtual image, and it is introduced how to be carried out. With the microstructure of recycled asphalt mixture obtained by virtual image technology,virtual specimens were generated,and the discrete element mesoscopic models were established. The method for determining the mesoscopic model parameters was summed up and proposed,i, e. the mesocopic model parameters of recycled asphalt mastic were obtained using the uniaxial static creep testing of recycled asphalt mastic. In order to improve the computational efficiency of the model, the viscoelastic parameters were transformed based on time-temperature equivalence principle. With the discrete el- ement method of PFC3D,the corresponding programs were written in FISH which is a language owned by PFC, the converted model parameters were in-putted, virtual uniaxial static creep experiments of recycled asphalt mixture were simulated,and compared with laboratory experiments＇ results of the recycled asphalt mixture,the reasonable effective- ness of virtual experiment was verified.