Buckling Mechanism Simulation for Thin-Wall Components Made by Laser Powder Bed Fusion

Abstract

The effect of part geometry on premature thin wall part failure in laser powder bed fusion (LPBF) is investigated using FEM simulation. Two FEM models are used to simulate the residual stress and buckling modes. Two experimental parts with different lengths are used for model validations. A LPBF FEM model evaluates the residual stress associated with the two experimental parts. A parametric buckling model is developed to determine the eigenvalues for 100 different part geometries including different part lengths (20-60 mm), widths (0.5-2 mm), and heights (10-50 mm). The results show that thin wall parts are more susceptible to buckling mode 1 when part length is small and to a combination of mode 1 and 3 when part length increases. In both cases the threshold stress for buckling is mostly sensitive to part thickness and height.