Webinar: Modified Inherent Strain Method for Additive Manufacturing
Prof. Albert To
April 20, 2021 at 3:00 p.m. (CEST, UTC+2)
Laser-based additive manufacturing (AM) has been widely used to produce metal products with complex geometries. However, the large thermal gradient caused by the fast, intense, and repeated laser scanning brings significant residual deformation and stress to the as-built metal parts, increasing manufacturing difficulty and geometrical inaccuracy as a result. To address this issue, a modified inherent strain method is proposed to predict the residual stress and deformation in as-built AM parts in an accurate and efficient manner. In the proposed model, the definition of inherent strains is modified to capture the effects of changing boundary conditions on the conversion of thermal energy into strain energy. This modified definition allows for the extraction of inherent strains from a detailed process simulation based on moving point heat source model in a representative domain. The extracted inherent strains can then be applied to a layerwise quasi-static finite element model to simulate the part-scale residual stress and deformation field. Both numerical and experimental studies are conducted to demonstrate the accuracy and efficiency of the modified model. Several applications of the proposed method will be highlighted in this talk which include support structure design, build orientation optimization, cracking prediction, and scanning path optimization.