Elasto-plastic residual stress analysis of selective laser sintered porous materials based on 3D-multilayer thermo-structural phase-field simulations  

作　　者：Yangyiwei Yang Somnath Bharech Nick Finger Xiandong Zhou Jörg Schröder Bai-Xiang Xu 

机构地区：[1]Mechanics of Functional Materials Division,Institute of Materials Science,Technische Universität Darmstadt,Darmstadt,Germany [2]Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province,College of Architecture and Environment,Sichuan University,Chengdu,China [3]Fakultät für Ingenieurwissenschaften,Abteilung Bauwissenschaften,Institut für Mechanik,Universität Duisburg-Essen,Essen,Germany

出　　处：《npj Computational Materials》2024年第1期2032-2048,共17页计算材料学(英文)

基　　金：We acknowledge the financial support of German Research Foundation(DFG)in the framework of the Collaborative Research Centre Transregio 270(CRC-TRR 270,project number 405553726,sub-projects A06 and A07);the Research Training Groups 2561(GRK 2561,project number 413956820,sub-project A4);the Priority Program 2122(SPP 2122,project number 493889809);X.Z.acknowledges the support from the National Natural Science Foundation of China(project number 12302231);Sichuan Science and Technology Program(project number 2023NSFSC0910);China Postdoctoral Science Foundation(project number 2023M732433).

摘　　要：Residual stress and plastic strain in additive manufactured materials can exhibit significant microscopic variation at the powder scale,profoundly influencing the overall properties of printed components.This variation depends on processing parameters and stems from multiple factors,including differences in powder bed morphology,non-uniform thermo-structural profiles,and interlayer fusion.In this research,we propose a powder-resolved multilayer multiphysics simulation scheme tailored for porous materials through the process of selective laser sintering.This approach seamlessly integrates finite element method(FEM)based non-isothermal phase-field simulation with thermo-elasto-plastic simulation,incorporating temperature-and phase-dependent material properties.The outcome of this investigation includes a detailed depiction of the mesoscopic evolution of stress and plastic strain within a transient thermo-structure,evaluated across a spectrum of beam power and scan speed parameters.Simulation results further reveal the underlying mechanisms.For instance,stress concentration primarily occurs at the necking region of partially melted particles and the junctions between different layers,resulting in the accumulation of plastic strain and residual stress,ultimately leading to structural distortion in the materials.Based on the simulation data,phenomenological relation regarding porosity/densification control by the beam energy input was examined along with the comparison to experimental results.Regression models were also proposed to describe the dependency of the residual stress and the plastic strain on the beam energy input.

关 键 词：stress RESIDUAL STRUCTURAL 

分 类 号：TG1[金属学及工艺—金属学]