Gallup Lucas, Trabia Mohamed, O'Toole Brendan, Fahmy Youssef
Department of Mechanical Engineering, University of Nevada, Las Vegas, NV 89154, USA.
Polymers (Basel). 2024 Dec 26;17(1):26. doi: 10.3390/polym17010026.
Thermoplastic polyurethanes (TPUs) are suited for fused deposition modeling (FDM) of parts that require high levels of flexibility and strength. Predicting the deformation of TPU parts produced using FDM may be difficult, especially under large deformations, as their constitutive models depend on the printing process parameters. The lack of understanding led to the absence of constitutive models for TPU parts produced using FDM. This work aims to identify accurate hyperelastic constitutive models. Six groups of uniaxial tensile specimens were produced using FDM. These groups were made with variations in two process parameters, which were infill geometry and extrusion nozzle temperature. Infill geometries either corresponded to a zero-deposition angle (wall-only) or an infill deposition of ±45° raster angle (infill-only). It was determined that a third-order Mooney-Rivlin constitutive model can accurately describe these six groups. A finite element analysis (FEA) of the experiments using the proposed constitutive models resulted in limited errors for all groups. The proposed approach was verified through a combination of experiments and FEA of FDM TPU components undergoing large deformation.
热塑性聚氨酯（TPU）适用于对柔韧性和强度要求较高的部件的熔融沉积成型（FDM）。预测使用FDM生产的TPU部件的变形可能很困难，尤其是在大变形情况下，因为它们的本构模型取决于打印工艺参数。由于缺乏了解，导致没有适用于使用FDM生产的TPU部件的本构模型。这项工作旨在确定准确的超弹性本构模型。使用FDM制作了六组单轴拉伸试样。这些组在两个工艺参数上有所变化，即填充几何形状和挤出喷嘴温度。填充几何形状要么对应于零沉积角度（仅壁），要么对应于±45°光栅角度的填充沉积（仅填充）。结果确定三阶Mooney-Rivlin本构模型可以准确描述这六组。使用所提出的本构模型对实验进行有限元分析（FEA），所有组的误差都有限。通过对经历大变形的FDM TPU部件进行实验和FEA相结合的方式，验证了所提出的方法。
