Modelling of yielding in additively manufactured materials using modified Tsai-Hill criterion

Additive manufacturing, particularly fused filament fabrication or fused deposition modeling, has grown explosively in the past ten years. Studies have begun to form a greater understanding of the influence of the print parameters on the mechanical properties of fused filament fabricated materials. Many of these studies have shown that the material properties of fused filament fabricated components vary highly with the parameters and settings used to print them. Therefore, growing efforts have been made to predict material properties based on print parameters using a reduced set of initial tests. In the present paper, a new method has been proposed to combine these theories into a unified predictive model based upon a modified Tsai-Hill criterion. A modified version of the Tsai-Hill criterion was developed for the prediction of the yield strength of additively manufactured materials without needing to test every print orientation. The equations developed for the new model were experimentally validated and proven to be capable of predicting the yield strength of these materials to an acceptable accuracy for mechanical design. The newly presented failure criterion is able to address the combined build and raster orientations, as well as the use of infill. This is a key advantage over most of the previous models which could only accommodate one print parameter at a time.