新拌自密实混凝土DEM接触模型开发及其数值实现

Development of DEM Model for Fresh Self-compacting Concrete and Its Numerical Implementation

考虑粗骨料间距影响,采用Hertz弹簧与"液桥"模型研究了自密实混凝土粗骨料之间的相互作用,利用面向对象的编程技术,自定义开发了自密实混凝土的离散元3D接触模型,并通过算例验证了程序编制的正确性。在此基础上,按照真实的粗骨料级配,利用自定义接触模型对L型箱试验进行数值模拟,对比结果表明,采用自定义模型模拟的流动时间和试验平均误差为4%,SCC最终流动形态的模拟结果和试验结果吻合较好。

With the influence of the distance between coarse aggregate under consideration, the Hertz springs and liquid-bridge model are combined to study the interaction of coarse aggregate of self-compacting concrete （ SCC）. The user-defined DEM （Discrete Element Method）3D contact model is developed by using object-oriented programming technique, and then the correctness of the program is verified through an example. Based on the researches, a DEM simulation is carried out on the L- box experiments of SCC, in which, the particles size distribution of aggregate in simulation coincides with actual coarse aggregate gradation. The flow time and flow pattern of simulation are compared with the values of laboratory experiments. The comparison results show that the average error of flow time is controlled within 4%, and the simulation of SCC final flowing shape is in good agreement with experimental value.