Warpage analysis and control of thin-walled structures manufactured by laser powder bed fusion

Abstract

Thin-walled structures are of great interest because of their use as lightweight components in aeronautical and aerospace engineering. The fabrication of these components by additive manufacturing (AM) often produces undesired warpage because of the thermal stresses induced by the manufacturing process and the components’ reduced structural stiffness. The objective of this study is to analyze the distortion of several thin-walled components fabricated by Laser Powder Bed Fusion (LPBF). Experiments are performed to investigate the sensitivity of the warpage of thin-walled structures fabricated by LPBF to different design parameters such as the wall thickness and the component height in several open and closed shapes. A 3D-scanner is used to measure the residual distortions in terms of the out-of-plane displacement. Moreover, an in-house finite element software is firstly calibrated and then used to enhance the original design in order to minimize the warpage induced by the LPBF printing process. The outcome of this shows that open geometries are more prone to warping than closed ones, as well as how vertical stiffeners can mitigate component warpage by increasing stiffness.