A Conceptual Design of Residual Stress Reduction with Multiple Shape Laser Beams In Direct Laser Deposition


Residual stress is a major problem in metal parts fabrication with the direct laser deposition (DLD) process due to severe temperature gradient around a molten pool. A three-dimensional finite element analysis (FEA) model with a simplified substrate clamping fixture modeling method is proposed, validated, and then implemented with a novel DLD heat input strategy in Ti-6Al-4V thin-wall structure fabrication, which was applied with multiple beam shapes, including a super-Gaussian beam, Gaussian beam, and inverse-Gaussian beam, to reduce residual stress in the final part. A regression model of the heat input and final part residual stress was obtained via a three-factor two-level full factorial design. An optimized heat input strategy was achieved based on response surface contour plots of the regression model.


Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center


The authors appreciate the sponsorship by Boeing through the Center for Aerospace Manufacturing Technologies (CAMT), National Science Foundation Grant # CMMI-1547042, and the Intelligent Systems Center (ISC) at Missouri S&T.

Keywords and Phrases

Aluminum; Aluminum alloys; Conceptual design; Deposition; Finite element method; Gaussian distribution; Laser beams; Regression analysis; Residual stresses; Substrates; Ternary alloys; Titanium; Titanium alloys; Direct laser deposition; Inverse gaussian; Metal parts fabrications; Regression model; Residual stress reductions; Super-Gaussian; Three dimensional finite element analysis; Ti-6 Al-4 V; Gaussian beams; Finite element analysis; Gaussian beam; Inverse-Gaussian beam; Super-Gaussian beam; Ti-6Al-4V

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


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© 2018 Elsevier, All rights reserved.

Publication Date

01 May 2018