Qualities of polymeric parts fabricated by material extrusion (ME) additive manufacturing is sensitive to the processing conditions. However, the linkages among ME polymers’ mesostructure, effective properties, and printing conditions are still not clear enough. In this context, the present work aims to establish a model capable of estimating the structure and elastic properties of unidirectionally extruded thermoplastic polymers just by setting printing conditions and intrinsic material properties as primary variables. To this end, according to the principle of mass conservation and a thermal-sintering model, the geometry of ME polymers, characterized by strands’ shape, size, and the bonding condition, are predicted firstly. Next, based on the representative volume element (RVE), numerical homogenization is conducted via the finite element method to gain the products’ orthotropic properties. Tests on ME Acrylonitrile Butadiene Styrene (ABS) products are also made. Our experimental results, together with the existing experimental data, verified the present model. Furthermore, parametric analyses are carried out. Effects of layer thickness, printing speed, flaw rate and extrusion temperature et al. on ME polymers’ porosity and mechanical behaviors are revealed, which may have important implications in the future ME additive manufacturing of thermoplastic polymers.

通过材料挤压（ME）增材制造制造的聚合物零件的质量对加工条件敏感。但是，ME聚合物的介观结构，有效性能和印刷条件之间的联系仍然不够清楚。在这种情况下，本工作旨在建立一个仅通过将印刷条件和固有材料性能设置为主要变量就能够估算单向挤出热塑性聚合物的结构和弹性性能的模型。为此，根据质量守恒原理和热烧结模型，首先预测了以链的形状，大小和结合条件为特征的ME聚合物的几何形状。接下来，基于代表性体积元素（RVE），通过有限元方法进行数值均质化以获得产品的正交异性。还对ME丙烯腈丁二烯苯乙烯（ABS）产品进行了测试。我们的实验结果以及现有的实验数据验证了该模型。此外，进行参数分析。层厚，印刷速度，缺陷率和挤出温度等的影响。揭示了ME聚合物的孔隙率和力学行为，这可能对热塑性聚合物未来的ME增材制造具有重要意义。进行参数分析。层厚，印刷速度，缺陷率和挤出温度等的影响。揭示了ME聚合物的孔隙率和力学行为，这可能对热塑性聚合物未来的ME增材制造具有重要意义。进行参数分析。层厚，印刷速度，缺陷率和挤出温度等的影响。揭示了ME聚合物的孔隙率和力学行为，这可能对热塑性聚合物未来的ME增材制造具有重要意义。