A Comparison of Predicted Distortion of a Manifold Fabricated by Laser Powder Bed Fusion Using Solid and Shell Element-based Finite Element Models

Abstract

This paper compares the predicted distortion of a manifold geometry fabricated by laser powder bed fusion between an established finite element model using solid elements and a newly developed in this paper finite element model using shell elements. The developed finite element models utilized two methods to induce a strain field (inherent strain and analytical thermal methods). The predicted distortions from these models were also compared with experimentally measured distortions. The results showed that the predicted distortion using solid elements is more suitable to predict the buckling effect on the manifold geometry. Despite that, the model using shell elements showed an accurate prediction of distortion in many areas of the manifold, and it proved to be computationally more efficient (2.4 times faster), this model showed lower accuracy in the prediction of distortion generated by buckling. However, shell elements could be used in other applications where the bucking is not the driving mechanism for the prediction of distortion in laser powder bed fusion or in applications where the accuracy of distortion is not a requirement (e.g., support structures).