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Fiber Breakage Model for Carbon Composite Stress Rupture Phenomenon: Theoretical Development and ApplicationsStress rupture failure of Carbon Composite Overwrapped Pressure Vessels (COPVs) is of serious concern to Science Mission and Constellation programs since there are a number of COPVs on board space vehicles with stored gases under high pressure for long durations of time. It has become customary to establish the reliability of these vessels using the so called classic models. The classical models are based on Weibull statistics fitted to observed stress rupture data. These stochastic models cannot account for any additional damage due to the complex pressure-time histories characteristic of COPVs being supplied for NASA missions. In particular, it is suspected that the effects of proof test could significantly reduce the stress rupture lifetime of COPVs. The focus of this paper is to present an analytical appraisal of a model that incorporates damage due to proof test. The model examined in the current paper is based on physical mechanisms such as micromechanics based load sharing concepts coupled with creep rupture and Weibull statistics. For example, the classic model cannot accommodate for damage due to proof testing which every flight vessel undergoes. The paper compares current model to the classic model with a number of examples. In addition, several applications of the model to current ISS and Constellation program issues are also examined.
Document ID
20100015408
Acquisition Source
Glenn Research Center
Document Type
Technical Memorandum (TM)
Authors
Murthy, Pappu L. N.
(NASA Glenn Research Center Cleveland, OH, United States)
Phoenix, S. Leigh
(Cornell Univ. Ithaca, NY, United States)
Grimes-Ledesma, Lorie
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 24, 2013
Publication Date
March 1, 2010
Subject Category
Composite Materials
Report/Patent Number
E-17092
NASA/TM-2010-215831
Funding Number(s)
WBS: WBS 869021.03.03.02.01
Distribution Limits
Public
Copyright
Public Use Permitted.
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