Fracture locus of additively manufactured AlSi10Mg alloy

In cellular structures, fracture occurs at various locations due to localized complex stress-and/or strain-state. Using the failure strain obtained from a conventional tensile test, the localized failure in cellular materials cannot be adequately predicted through finite element analysis owing to localized triaxial stress -state. Moreover, complex build orientation of different ligaments influences the macroscopic performance of cellular structures considerably. In order to accurately predict the failure of cellular structures using numerical approach, failure strain with respect to both the stress triaxiality and the build orientation ought to be considered. The fracture loci of Laser Powder Bed Fusion (LPBF) fabricated AlSi10Mg alloy were determined experimentally for different build orientations to develop a predictive capability. Moreover, quasi-static compression tests were performed on an additively manufactured re-entrant cellular structures and the experimental results were corroborated by the numerical predictions obtained using fracture loci. The numerical model which considers triaxial fracture locus predicts the deformation mode and the fracture location of the re-entrant structure more accurately than the model that considers a simple uniaxial tensile failure.

Automated summary

Fracture occurs in cellular structures due to localized complex stress and/or strain state, making it difficult to accurately predict failure using traditional testing methods and finite element analysis. The build orientation of different ligaments also significantly affects the macroscopic performance of cellular structures. In order to improve numerical predictions, the failure strain should be considered in relation to stress triaxiality and build orientation. Experimental determination of fracture loci in AlSi10Mg alloy fabricated using Laser Powder Bed Fusion (LPBF) for different build orientations helps in developing predictive capabilities. Numerical models considering triaxial fracture loci provide more accurate predictions of deformation mode and fracture location in re-entrant structures compared to models that assume simple uniaxial tensile failure.