Effects of interlayer notch and shear stress on interlayer strength of 3D printed cement paste
Effects of interlayer notch and shear stress on interlayer strength of 3D printed cement paste
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DOI：
10.1016/j.addma.2020.101390
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发表时间：
2020-12-01
影响因子：
11
通讯作者：
Li, Hua
中科院分区：
文献类型：
--
作者：
He, Lewei;Chow, Wai Tuck;Li, Hua
为了研究层间缺口和剪切应力对3D打印水泥浆层间强度的影响，重点研究了喷嘴形状、喷嘴高度和打印速度对层间强度的影响。实验观察到，与矩形喷嘴相比，圆形喷嘴打印的水泥浆一般具有更高的层间强度。如果层间缺口处理不当，较小的喷嘴高度可能会损害层间强度。此外，更高的打印速度略微增加了层间强度，显示出更高生产率的前景。理论上，通过有限元和计算流体动力学模拟，创新性地用层间缺口与接触面剪应力耦合来解释实验现象。因此，减小层间缺口、提高层间剪应力成为3D打印水泥浆体的关键。
In this paper for investigation of the effect of interlayer notch and shear stress on interlayer strength of 3D printed cement paste, experimental work is conducted with emphasis on the effects of nozzle shape, nozzle height and printing speed on the interlayer strength. It is observed experimentally that the cement paste printed by the circular nozzle generally achieves a higher interlayer strength, compared with that printed by the rectangular nozzle. A smaller nozzle height may impair the interlayer strength if the interlayer notch is not treated properly. In addition, a higher printing speed marginally increases the interlayer strength, showing the promise of a higher productivity. Theoretically, the experimental phenomena are innovatively explained by the interlayer notch coupled with shear stress on the contact surface, through finite-element and computational-fluid-dynamics simulations. Therefore, reducing the interlayer notch and increasing the interlayer shear stress become crucial in the cement paste for 3D printing process.