【摘要】 构建一个描述粘塑性变形的组合体,引入非线性粘滞阻尼器,假定阻尼器所受应力与蠕变加速度成正比,在Burgers模型中串联该组合体,得到一个能够完整描述沥青砂三个蠕变过程的非线性流变模型,理论推导和分析了该模型蠕变本构方程。进行了沥青砂试件在40℃、不同应力水平下单轴压缩蠕变试验,编制非线性拟合程序求得该模型参数,并得到模型参数与加载应力的函数关系。为验证模型有效性,本文模型预测与Bur-gers模型预测及实验结果进行对比,结果表明,本文模型与实验结果吻合更好,完整反映了沥青砂三个蠕变阶段变形特征。更多还原

【Abstract】 An element describing viscoplastic deformation was presented in this paper,by introducing a nonlinear viscous dashpot which its stress is proportion to creep acceleration.Burgers model,which often describes the first two creep stages,was extended to a non-linear rheological model by combining with the element in series.In order to determine the non-linear model parameters,uniaxial compression tests were performed at 40℃ under the controlled-stress mode with different stress amplitudes(0.1,0.15,0.2,0.25,0.3 MPa).The model creep representation was deduced for the uniaxial loading condition and the model parameters were attained by a nonlinear fitting program.Comparison between the proposed model and Burgers model prediction with experimental results show that the model successfully describes the total deformation behavior of asphalt sand mixture and has a better agreement with the experimental results.更多还原