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Modified Displacement Transfer Functions for Deformed Shape Predictions of Slender Curved Structures with Varying CurvativesTo eliminate the need to use finite-element modeling for structure shape predictions, a new method was invented. This method is to use the Displacement Transfer Functions to transform the measured surface strains into deflections for mapping out overall structural deformed shapes. The Displacement Transfer Functions are expressed in terms of rectilinearly distributed surface strains, and contain no material properties. This report is to apply the patented method to the shape predictions of non-symmetrically loaded slender curved structures with different curvatures up to a full circle. Because the measured surface strains are not available, finite-element analysis had to be used to analytically generate the surface strains. Previously formulated straight-beam Displacement Transfer Functions were modified by introducing the curvature-effect correction terms. Through single-point or dual-point collocations with finite-elementgenerated deflection curves, functional forms of the curvature-effect correction terms were empirically established. The resulting modified Displacement Transfer Functions can then provide quite accurate shape predictions. Also, the uniform straight-beam Displacement Transfer Function was applied to the shape predictions of a section-cut of a generic capsule (GC) outer curved sandwich wall. The resulting GC shape predictions are quite accurate in partial regions where the radius of curvature does not change sharply.
Document ID
20140010280
Acquisition Source
Armstrong Flight Research Center
Document Type
Technical Memorandum (TM)
Authors
Ko, William L.
(NASA Armstrong Flight Research Center Edwards, CA, United States)
Fleischer, Van Tran
(NASA Armstrong Flight Research Center Edwards, CA, United States)
Date Acquired
July 29, 2014
Publication Date
May 1, 2014
Subject Category
Structural Mechanics
Report/Patent Number
AFRC-E-DAA-TN13627
NASA/TM-2014-216660
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Keywords
displacement transfer functions
deflection equations
displacement theory
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