摘要
采用加载0.1 s、卸载0.9 s的半正弦波间歇荷载模拟路面实际的车辆荷载,利用线性Drucker-Prager蠕变模型对重复荷载下AC-13C基质、改性沥青混合料的变形进行黏弹塑性数值模拟,预测得到的变形与实测变形相比非常一致。沥青混合料的蠕变应变随着时间的增长而增大,初期增长率大而后期增长率小。在沥青混合料未屈服时,蠕变应变就是沥青混合料的永久应变;当沥青混合料发生屈服,产生了不随时间变化的塑性应变,此时蠕变应变加上塑性应变即为沥青混合料的永久应变。结果表明线性Drucker-Prager蠕变模型可以预测重复荷载作用下沥青混合料的变形,可用于移动荷载下沥青混凝土路面结构的力学响应分析。
A half-sinusoids load with 0. 1 s loading duration and 0. 9 s unloading duration is used to simulate the dynamic vehicle load and numerical simulation for deformation of asphalt mixtures under repeated load is carried out via visco-elastoplastic finite element method based on linear Drucker-Prager creep model. The predicted deformation of AC-13C unmodified and modified asphalt mixtures under repeated load shows an excellent correlation with the measured deformation. Creep strain of asphalt mixtures increases with loading time. Strain rate is larger at initial period and smaller at later period. When asphalt mixtures do not reach yielding, then only creep strain is occurred. If asphalt mixtures yielded, then irrecoverable and time-independent plastic strain occurred. Permanent strain of asphalt mixtures is composed of creep strain and plastic strain. The results show that linear Drueker-Prager creep model could well predict permanent deformation of asphalt mixtures. Furthermore it can be used to analyze dynamic mechanical response of asphalt concrete pavement structure under moving loads.
出处
《公路》
北大核心
2010年第4期138-143,共6页
Highway
基金
国家自然科学基金
项目编号50808087
