【摘要】 为研究循环荷载加大混凝土徐变的内因,以循环荷载和恒荷载下混凝土徐变试验结果为基础,基于多孔介质理论的混凝土徐变模型,编制了徐变模拟分析程序,在细观尺度下模拟了受循环荷载作用的混凝土内部骨料、砂浆与水的耦合过程,得到了宏观尺度下模型内部节点位移过程图、细观尺度下水分流速分布图、孔隙压力消散过程图、等效应力变化图。研究结果表明:(1)数值模拟方法可以描述细观尺度下混凝土内部骨料、砂浆、水分的运动规律;(2)与恒定荷载相比,循环荷载通过影响水分的运动,加快了骨料与砂浆的内力重分布速度,推进了混凝土固相的受力均匀化的过程,从而加大混凝土徐变。更多还原

【Abstract】 In order to explore the concrete creep rule under cyclic load,the concrete creep model based on the theory of porous media was supposed to compile the creep analysis program,the program simulates the interaction between aggregate,mortar and water at meso-level.The node displacement rule at macro-level and the distribution rule of liquid flowing rate,pore pressure,equivalent stress from numerical simulation were analyzed by comparing the laboratory test date with numerical simulation results.The results show that the finite element program which combined theory is capable of describing the movement rule of aggregate,mortar and water inside the concrete at meso-level;Compared with numerical simulation results under static load,the speed of water,aggregate and mortar appears more faster is the main cause for increasing concrete creep under cyclic load.更多还原