混凝土动态3D打印过程温度应力数值仿真分析

Numerical simulation analysis on temperature stress during dynamic process of 3D printed concrete

3D打印混凝土在水利水电领域有着广阔的发展前景,但温度应力的影响使其发展受到限制,为此需要研究如何降低其构件的温度应力。由3D打印混凝土的工艺特点可知,通过外部条件对其温度进行控制是不可行的。因此,从混凝土动态3D打印成型的工艺参数出发,对其温度场、应力场进行了研究,以期得到工艺参数对其温度应力的影响。通过数值模拟的方法,得出了混凝土内部各点温度随时间的变化以及打印速度、打印层厚和初始打印温度等对3D打印混凝土构件内部温度变化的影响。结果表明,适当地增大混凝土的打印速度、减小打印层厚、降低初始打印温度,可以降低混凝土的最大应力,且打印速度为3. 0 m/min、打印层厚为0. 10 m、初始打印温度为12℃时,典型层的最大应力最低。

3D printed concrete has a broad prospect in the field of water resources and hydropower engineering,but its development is restricted by the influence of temperature stress,so it is necessary to study how to reduce the temperature stress of its component.From the technological characteristics of3D printed concrete,it is known that it is infeasible to control its temperature through the relevant external conditions.Therefore,the temperature field and stress field of3D printed concrete are studied herein from the aspect of the technological parameters of the dynamic fabrication of the concrete,so as to obtain the influences from the technological parameters on its temperature stress.Through numerical simulation method,the influences from the timedependent changes of the temperatures at all the relevant points inside of the concrete as well as the printing speed,printing thickness,initial printing temperature,etc.on the change of the internal temperature of the component of3D printed concrete are obtained.The result shows that the maximum stress of the concrete can be reduced through appropriately increasing the printing speed,decreasing the printing thickness and reducing the initial printing temperature,moreover,the maximum stress of the typical layer is the lowest when the printing speed is3m/min,the printing thickness is0.1m,and the initial temperature is12℃.