Title
Accelerated Life Testing of Subsea Equipment Under Hydrostatic Pressure
Abbreviated Journal Title
Mar. Technol. Soc. J.
Keywords
accelerated life testing; high pressure; life prediction; subsea; reliability; MODEL; RELIABILITY; INFERENCE; Engineering, Ocean; Oceanography
Abstract
Accelerated life testing (ALT) is an effective method of demonstrating and improving product reliability in applications where the products are expected to perform for a long period of time. ALT accelerates a given failure mode by testing at amplified stress level(s) in excess of operational limits. Statistical analysis (parameter estimation) is then performed on the data, based on an acceleration model to make life predictions at use level. The acceleration model thus forms the basis of ALT methodology. Well-established accelerated models such as the Arrhenius model and the Inverse Power Law (IPL) model exist for key stresses such as temperature and voltage, but there are other stresses, like subsea pressure, where there are no clear model of choice. This research proposes a pressure-life (acceleration) model for the first time for life prediction under subsea pressure for key mechanical/physical failure mechanisms. Three independent accelerated tests were conducted, and their results were analyzed to identify the best model for the pressure-life relationship. The testing included material tests in standard coupons to investigate the effect of subsea pressure on key physical, mechanical, and electrical properties. Tests were also conducted at the component level on critical components that function as a pressure barrier. By comparing the likelihood values of multiple reasonable candidate models for the individual tests, the exponential model was identified as a good model for the pressure-life relationship. In addition to consistently providing good fit among the three tests, the exponential model was also validated with over 10 years of field data and demonstrated several characteristics that enable robust life predictions in a variety of scenarios. In addition, the research also used the process of Bayesian analysis to incorporate prior information from field and test data to bolster the results and increase the confidence in the predictions from the proposed model.
Journal Title
Marine Technology Society Journal
Volume
45
Issue/Number
5
Publication Date
1-1-2011
Document Type
Article
Language
English
First Page
42
Last Page
54
WOS Identifier
ISSN
0025-3324
Recommended Citation
"Accelerated Life Testing of Subsea Equipment Under Hydrostatic Pressure" (2011). Faculty Bibliography 2010s. 1996.
https://stars.library.ucf.edu/facultybib2010/1996
Comments
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