Modeling of residual stresses in combined additive manufacturing and machining processes
department or school: Applied Science, Faculty of
department or school: Mechanical Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Yang, Shenliang
issued: 2025-05-20T17:24:11Z
issued: 2025
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: As a widely used metal additive manufacturing technology, directed energy deposition (DED) provides a cost-effective solution for repairing and remanufacturing high-performance metallic components. Nevertheless, their industrial applications are limited by excessive geometric distortion (caused by high-gradient bulk residual stress) and poor surface quality. To achieve desired surface finishes, post-machining of DED is usually performed, which introduces additional surface residual stress. These residual stresses can compromise structural integrity, fatigue life, and corrosion resistance. Guided by three critical and practical research questions—(1) how to efficiently predict DED-induced bulk residual stress, (2) how to accurately simulate surface residual stress created by machining, and (3) how DED-induced bulk stress interacts with machining to generate final surface stress—this thesis develops physics-based models to understand the formation mechanism of residual stresses in combined DED and machining processes. First, analytical models are proposed to determine thermo-mechanical responses in single-material and functionally graded DED processes. These models employ finite difference methods for predicting temperature cycles, modified Green’s functions to quantify thermal stress, and radial return methods to update plastic stress, which features the material addition as the heat source moves in each deposition layer in DED. The frameworks effectively demonstrate how DED deposition conditions and material gradients influence bulk residual stress. Second, finite element method (FEM) models are presented to predict machining-induced surface residual stress in conventionally wet machining processes and high-speed machining processes with serrated chip generation. The results quantitatively illustrate the mitigation of surface tensile residual stress due to applying cutting fluids and the fluctuation of surface residual stress caused by periodic shear localization in…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/91164
note: Modelling of Residual Stresses inCombined Additive Manufacturingand Machining ProcessesbyShenliang YangA THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinThe Faculty of Graduate and Postdoctoral Studies(Mechanical Engineering)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)May 2025© Shenliang Yang 2025The following individuals certify that they have read, and recommend to the Faculty of Graduateand Postdoctoral Studies for acceptance, the dissertation entitled:Modelling of Residual Stresses in Combined Additive Manufacturing and Machining Processessubmitted by Shenliang Yang in partial fulfilment of the requirements forthe degree of Doctor of Philosophyin Mechanical EngineeringExamining Committee:Xiaoliang Jin, Associate Professor, Mechanical Engineering, UBCSupervisorAdam Clare, Professor, Mechanical Engineering, UBCCo-supervisorRajeev Jaiman, Professor, Mechanical Engineering, UBCUniversity ExaminerEdouard Asselin, Professor, Materials Engineering, UBCUniversity ExaminerIsmail Lazog˘lu, Professor, Mechanical Engineering, Koc UniversityExternal ExaminerAdditional Supervisory Committee Members:Yusuf Altintas, Professor, Mechanical Engineering, UBCSupervisory Committee MemberGary Schajer, Professor, Mechanical Engineering, UBCSupervisory Committee MemberChadwick Sinclair, Professor, Materials Engineering, UBCSupervisory Committee MemberiiAbstractAs a widely used metal additive manufacturing technology, directed energy deposition (DED) pro-vides a cost-effective solution for repairing and remanufacturing high-performance metallic com-ponents. Nevertheless, their industrial applications are limited by excessive geometric distortion(caused by high-gradient bulk residual stress) and poor surface quality. To achieve desired surfacefinishes, post-machining of DED is usually performed, which introduces additional surface resid-ual stress. These residual stresses can compromise structural integrity, fatigue life, and corrosionres…
has type: Thesis/Dissertation
date issued: 2025-11
is shown at: 10.14288/1.0448918
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Jin, Xiaoliang
contributor: Clare, Adam T.
type: Text
identifier URI: http://hdl.handle.net/2429/91164