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Distortion and Residual Stress Control in Integrally Stiffened Structure Produced by Direct Metal Deposition2-D thermo-mechanical model developed to characterize distortion and residual stresses in integral structure produced by DMD. Demonstrated as a tool to guide experimental development of DMD fabrication process for aero structures. Distortion and residual stresses are local to deposit. Most distortion develops during deposition of the first few layers; Little change in distortion or residual stresses after fifth deposit layer Most of distortion is localized just beneath the build. Thicker build plates and the use of build lands results in greatest decrease in levels of distortion. Pre-straining shown to reduce distortion. Difficult to implement, particularly for complex stiffener arrays. Clamp position has complex effect on distortion and stresses. Overall distortion reduced with decreasing clamp clearance. Larger clamp clearances induce bending. Use of pre-heat and active cooling show minor influence on panel distortion. Generate changes in thermal gradients in the build plate.
Document ID
20080013388
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Lin, Shih-Yung (Lockheed Martin Mission Services Co. MD, United States)
Hoffman, Eric K. (NASA Langley Research Center Hampton, VA, United States)
Domack, Marcia S. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 24, 2013
Publication Date
June 27, 2007
Subject Category
Metals And Metallic Materials
Meeting Information
Meeting: AeroMat 2007 - 18th AeroMat Conference and Exposition
Location: Baltimore, MD
Country: United States
Start Date: June 25, 2007
End Date: June 28, 2007
Funding Number(s)
WBS: WBS 561581.02.08.07.15.03
Distribution Limits
Public
Copyright
Public Use Permitted.

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