PLA材料在3D打印过程中的热应力场分析

Thermal Stress Coupling Field Analysis of PLA Materials in 3D Printing Process

针对PLA材料在3D打印过程中因热应力的影响而造成成型件精度降低的问题,采用ANSYS的APDL语言编写命令流,实现了模型建立、网格划分、载荷施加以及模拟计算,并将温度场仿真结果作为载荷加载到应力场分析中,得出了模型受热应力而发生形变的情况——模型的主要形变范围在模型的边缘部分,而中心部分的形变量较小,同时,在冷却完成后,模型整体尺寸略有缩小.因打印过程不是一次成型过程,模型在打印过程中的温度场梯度较大,造成应力场分布不均匀,导致模型翘曲变形.通过实验验证对比分析,实验结果与模拟结果基本符合.该分析方法可以对以后探究PLA材料在3D成型过程中的最合适打印条件提供一定的帮助。

In the 3D printing process of the PLA materials, the precision of the forming parts was reduced due to the influence of the thermal stress. Using APDL of ANSYS to edit command stream , to create model, to divide grid, to define boundary and to simulate, the temperature field simulation results which were loaded into the stress field analysis by using ANSYS software were obtained. The deformation of the model affected by the thermal stress was obtained - the main deformation range of the model was situated at the boundary of the print part, and the deformation of the central of the part was small. At the same time, the overall size of the model was slightly reduced after cooling. The printing process was not a molding process and the temperature field gradient of the model was large during the printing process, resulting in uneven distribution of the stress field and warpage deformation of the model. The analytical method could be helpful to explore the optimal printing conditions of PLA materials in the 3D forming process in the future.