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Implementation of Fiber Optic Sensing System on Sandwich Composite Cylinder Buckling TestThe National Aeronautics and Space Administration (NASA) Engineering and Safety Center Shell Buckling Knockdown Factor Project is a multicenter project tasked with developing new analysis-based shell buckling design guidelines and design factors (i.e., knockdown factors) through high-fidelity buckling simulations and advanced test technologies. To validate these new buckling knockdown factors for future launch vehicles, the Shell Buckling Knockdown Factor Project is carrying out structural testing on a series of large-scale metallic and composite cylindrical shells at the NASA Marshall Space Flight Center (Marshall Space Flight Center, Alabama). A fiber optic sensor system was used to measure strain on a large-scale sandwich composite cylinder that was tested under multiple axial compressive loads up to more than 850,000 lb, and equivalent bending loads over 22 million in-lb. During the structural testing of the composite cylinder, strain data were collected from optical cables containing distributed fiber Bragg gratings using a custom fiber optic sensor system interrogator developed at the NASA Armstrong Flight Research Center. A total of 16 fiber-optic strands, each containing nearly 1,000 fiber Bragg gratings, measuring strain, were installed on the inner and outer cylinder surfaces to monitor the test article global structural response through high-density real-time and post test strain measurements. The distributed sensing system provided evidence of local epoxy failure at the attachment-ring-to-barrel interface that would not have been detected with conventional instrumentation. Results from the fiber optic sensor system were used to further refine and validate structural models for buckling of the large-scale composite structures. This paper discusses the techniques employed for real-time structural monitoring of the composite cylinder for structural load introduction and distributed bending-strain measurements over a large section of the cylinder by utilizing unique sensing capabilities of fiber optic sensors.
Document ID
20180000578
Acquisition Source
Armstrong Flight Research Center
Document Type
Conference Paper
Authors
Pena, Francisco
(NASA Armstrong Flight Research Center Edwards, CA, United States)
Richards, W. Lance
(NASA Armstrong Flight Research Center Edwards, CA, United States)
Parker, Allen R.
(NASA Armstrong Flight Research Center Edwards, CA, United States)
Piazza, Anthony
(NASA Armstrong Flight Research Center Edwards, CA, United States)
Schultz, Marc R.
(NASA Langley Research Center Hampton, VA, United States)
Rudd, Michelle T.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Gardner, Nathaniel W.
(Analytical Services and Materials, Inc. Hampton, VA, United States)
Hilburger, Mark W.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
January 17, 2018
Publication Date
January 8, 2018
Subject Category
Structural Mechanics
Report/Patent Number
AFRC-E-DAA-TN47969
Meeting Information
Meeting: AIAA SciTech 2018 Conference
Location: Kissimmee, FL
Country: United States
Start Date: January 8, 2018
End Date: January 12, 2018
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Keywords
FOS
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