Mixed-mode fracture prediction of acrylonitrile butadiene styrene material fabricated via fused deposition modeling

Fused deposition modeling is one of the additive manufacturing techniques that is used for rapid manufacturing and prototyping, in various industries. Due to the layer-wise fabrication routine in the fused deposition modeling process, the final fabricated products often show anisotropic behavior. As a result, to investigate the mechanical performance of the three-dimensional-printed parts, complex and time-consuming analyses are required. The main purpose of the current research paper is to determine whether the isotropic assumption of material using maximum tangential stress and mean stress criteria is capable of predicting the mixed-mode fracture resistance of the three-dimensional -printed parts. Here, three different building conditions are considered for fabricating tensile and fracture specimens, and various mechanical and fracture characteristics are evaluated. Finite element simulations of the test specimens are executed and the stress results are used as input for fracture prediction of the fused deposition modeling parts. Two different cases are considered for isotropic assumptions wherein the first case (case A), each fracture specimen is modeled by using its own direct mechanical properties. While in the second case (case B), the average mechanical properties are used for modeling the cracked specimens. The results showed that both maximum tangential stress and mean stress criteria can predict the fracture loads of the fused deposition modeling parts, without the need for complex and time-consuming analyses associated with fully anisotropic materials. In addition, an improvement of the predictions was observed while using case A compared to case B.