The main objective of this manuscript is to evaluate the capability of the fracture criteria and numerical methods to predict fracture properties of the specimens fabricated using the Fused Deposition Modelling (FDM) 3D-Printing method. Different thermoplastic materials are 3D printed in Semi-Circular Bending (SCB) specimens configuration and subjected to three-point bending loading to investigate their failure behaviour, including final load-bearing and crack path trajectory. The Acrylonitrile Butadiene Styrene (ABS) due to its brittle behavior, was selected for the mixed mode fracture study. The SCB samples with various pre-crack angles indicating different modes of loading conditions are manufactured. Cracked SCB specimens are produced with and without geometrical discontinuities as holes to verify the effect of stress concentration on their fracture behavior. The results of the three-point bending tests demonstrated that the Extended Finite Element-Cohesive Zone Model (XFEM-CZM) and Average Strain Energy Density (ASED) criterion are capable of predicting the fracture behavior of the 3D-Printed ABS material under mixed-mode I/II loading. The appropriate XFEM-CZM damage criterion was used to estimate the crack growth path. The final failure load was obtained using the ASED and XFEM criteria. The maximum error rate between the experimental results and the presented theories was 10%, which confirms the employed criteria' accuracy. The results showed that a stress raiser like a hole in the 3D-Printed specimens might reduce the loading capacity of the material by 17%.

该手稿的主要目的是评估断裂标准和数值方法的能力，以预测使用熔融沉积建模（FDM）3D打印方法制造的试样的断裂特性。不同的热塑性材料以半圆弯曲（SCB）样本配置进行3D打印，并经受三点弯曲载荷以研究其破坏行为，包括最终的承载力和裂纹路径轨迹。由于其脆性，丙烯腈-丁二烯-苯乙烯（ABS）被选择用于混合模式断裂研究。制造了具有各种预裂纹角的SCB样品，这些样品表明了不同的加载条件模式。产生裂纹的SCB标本时有无几何不连续性作为孔，以验证应力集中对其断裂行为的影响。三点弯曲测试的结果表明，扩展有限元内聚区模型（XFEM-CZM）和平均应变能密度（ASED）准则能够预测3D打印ABS材料在混合压力下的断裂行为。模式I / II加载。适当的XFEM-CZM损伤准则用于估计裂纹扩展路径。使用ASED和XFEM标准获得最终的失败载荷。实验结果与提出的理论之间的最大错误率为10％，这证实了所采用标准的准确性。