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A Reliability Comparison of Classical and Stochastic Thickness Margin Approaches to Address Material Property Uncertainties for the Orion Heat ShieldThe Orion Thermal Protection System (TPS) margin process uses a root-sum-square approach with branches addressing trajectory, aerothermodynamics, and material response uncertainties in ablator thickness design. The material response branch applies a bond line temperature reduction between the Avcoat ablator and EA9394 adhesive by 60 C (108 F) from its peak allowed value of 260 C (500 F). This process is known as the Bond Line Temperature Material Margin (BTMM) and is intended to cover material property and performance uncertainties. The value of 60 C (108 F) is a constant, applied at any spacecraft body location and for any trajectory. By varying only material properties in a random (monte carlo) manner, the perl-based script mcCHAR is used to investigate the confidence interval provided by the BTMM. In particular, this study will look at various locations on the Orion heat shield forebody for a guided and an abort (ballistic) trajectory.
Document ID
20180001289
Acquisition Source
Ames Research Center
Document Type
Presentation
Authors
Sepka, Steve
(Analytical Mechanics Associates, Inc. Moffett Field, CA, United States)
Vander Kam, Jeremy
(NASA Ames Research Center Moffett Field, CA, United States)
McGuire, Kathy
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
February 20, 2018
Publication Date
January 10, 2018
Subject Category
Fluid Mechanics And Thermodynamics
Aerodynamics
Report/Patent Number
ARC-E-DAA-TN51125
Meeting Information
Meeting: AIAA SciTech 2018
Location: Kissimmee, FL
Country: United States
Start Date: January 8, 2018
End Date: January 12, 2018
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
CONTRACT_GRANT: NNA15BB15C
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
FIAT
CHAR
BTMM
mcCHAR
TPS
mcFIA
materials
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