Coupling Grain Structure and Crystal Plasticity for Track- and Part-Scale Simulations of L-PBF Additive Manufacturing
Guest Speaker： Assoc.Prof. Yancheng Zhang，MINES Paris - PSL ，France
Inviter: Ass.Prof. Neng Ren
Date&Time: Tuesday, 11 Nov. 15:00-16:30
Venue: Yiucheng Lecture Hall (500), Xu Zuayo Building
Biography:
Dr. Yancheng Zhang received his Bachelor’s and Master’s degrees in Engineering from Northeastern University (China) in 2005 and 2008, respectively. In October 2011, he obtained his Ph.D. in Mechanical Engineering from INSA Lyon (France). From November 2011 to September 2015, he conducted research on fracture mechanics of nanocomposite at the Institute of Structural Mechanics (Bauhaus University Weimar, Germany) and reduced-order modeling of welding processes at the LaMCoS laboratory (INSA Lyon, France).
In October 2015, he joined MINES Paris - PSL (France) and was promoted to Associate Professor with tenure in October 2018. In October 2025, he obtained the Habilitation à Diriger des Recherches (HDR), the French professor qualification. Currently, he works at the Centre for Material Forming (CEMEF) of MINES Paris - PSL, focusing on numerical simulation of additive manufacturing (3D printing), model order reduction, and constitutive modeling of single-crystal nickel-based superalloys. His research has been published in leading international journals such as Comput. Methods. Appl. Mech.， Eng. Int. J. Numer. Meth. Eng.，Addit. Manuf., J. Mater. Process. Technol. He also co-authored a book chapter in Numerical Simulation of Additive Manufacturing Processes. In 2021, he was awarded a French National Research Agency (ANR) Young Investigator Grant (ANR-JCJC). In addition, he developed AM-Multi, a software application dedicated to model reduction in additive manufacturing simulations. He also serves as a topic editor for the journal of Mechanical Sciences.
Abstract:
Methods of coupling grain structures with anisotropic behavior have been developed to predict the mechanical response of metallic alloys during L-PBF process. At the melt pool scale, epitaxial grain growth can be modelled using a CAFE (cellular automaton/finite elements) formulation within an existing thermo-hydraulic numerical model. Crystal viscoplasticity is adopted as the constitutive law for describing the mechanical behavior of the grain structure over a wide temperature range. The different features of this approach are discussed in relation to L-PBF of 316L stainless steel. At the part scale, the grain structure can no longer be computed simultaneously with the heat transfer and mechanical solution processes. This limitation arises because accurately simulating transient melting and solidification throughout the entire L-PBF process of a component is computationally prohibitive. To address this, the proposed strategy involves pre-calculating the grain structure at the part scale using an original hybrid cellular automaton methodology. This approach generates the grain structure while accounting for the detailed scan path, under the assumption of a steady-state local thermal distribution and melt pool geometry. Once this pre-computation is completed, the resulting grain structure is incorporated into the crystal viscoplasticity model for each newly built layer, within a layer-by-layer thermomechanical simulation framework. Since the finite element mesh may not fully resolve the fine details of the grain structure, a homogenization procedure is applied to represent multiple grains within each finite element. Finally, stress and distortion predictions are presented for a small turbine propeller made of IN718.