Chen X, Ashcroft I A, Wildman R D, Tuck C J
Additive Manufacturing and 3D Printing Research Group, Faculty of Engineering , University of Nottingham , NG7 2RD, UK.
Proc Math Phys Eng Sci. 2015 Nov 8;471(2183):20150477. doi: 10.1098/rspa.2015.0477.
A method using experimental nanoindentation and inverse finite-element analysis (FEA) has been developed that enables the spatial variation of material constitutive properties to be accurately determined. The method was used to measure property variation in a three-dimensional printed (3DP) polymeric material. The accuracy of the method is dependent on the applicability of the constitutive model used in the inverse FEA, hence four potential material models: viscoelastic, viscoelastic-viscoplastic, nonlinear viscoelastic and nonlinear viscoelastic-viscoplastic were evaluated, with the latter enabling the best fit to experimental data. Significant changes in material properties were seen in the depth direction of the 3DP sample, which could be linked to the degree of cross-linking within the material, a feature inherent in a UV-cured layer-by-layer construction method. It is proposed that the method is a powerful tool in the analysis of manufacturing processes with potential spatial property variation that will also enable the accurate prediction of final manufactured part performance.
已开发出一种使用实验性纳米压痕和反向有限元分析（FEA）的方法，该方法能够准确确定材料本构特性的空间变化。该方法用于测量三维打印（3DP）聚合物材料中的特性变化。该方法的准确性取决于反向有限元分析中使用的本构模型的适用性，因此对四种潜在的材料模型：粘弹性、粘弹性-粘塑性、非线性粘弹性和非线性粘弹性-粘塑性进行了评估，其中后者与实验数据拟合最佳。在3DP样品的深度方向上观察到材料特性的显著变化，这可能与材料内部的交联程度有关，这是紫外线固化逐层构建方法所固有的一个特征。有人提出，该方法是分析具有潜在空间特性变化的制造工艺的有力工具，这也将能够准确预测最终制造零件的性能。
