Statistical characterization of the impact strengths of vapor-grown carbon nanofiber/vinyl ester nanocomposites using a central composite design

2012 ◽  
Vol 128 (2) ◽  
pp. 1070-1080 ◽  
Author(s):  
Glenn W. Torres ◽  
Sasan Nouranian ◽  
Thomas E. Lacy ◽  
Hossein Toghiani ◽  
Charles U. Pittman ◽  
...  
Keyword(s):  
Central Composite Design ◽  
Vinyl Ester ◽  
Carbon Nanofiber ◽  
Statistical Characterization ◽  
The Impact ◽  
Central Composite ◽  
Vapor Grown Carbon Nanofiber

Creep characterization of vapor-grown carbon nanofiber/vinyl ester nanocomposites using a response surface methodology

2015 ◽  
Vol 132 (26) ◽  
pp. n/a-n/a
Author(s):  
Daniel A. Drake ◽  
Rani W. Sullivan ◽  
Thomas E. Lacy ◽  
Charles U. Pittman ◽  
Hossein Toghiani ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Vinyl Ester ◽  
Carbon Nanofiber ◽  
Vapor Grown Carbon Nanofiber

Molecular dynamics simulations of oxidized vapor-grown carbon nanofiber surface interactions with vinyl ester resin monomers

Carbon ◽  
2012 ◽  
Vol 50 (3) ◽  
pp. 748-760 ◽  
Author(s):  
Changwoon Jang ◽  
Sasan Nouranian ◽  
Thomas E. Lacy ◽  
Steven R. Gwaltney ◽  
Hossein Toghiani ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Vinyl Ester ◽  
Carbon Nanofiber ◽  
Surface Interactions ◽  
Vinyl Ester Resin ◽  
Dynamics Simulations ◽  
Vapor Grown Carbon Nanofiber

Ice Gouge Reliability of Offshore Arctic Pipelines

2007 ◽  
Author(s):  
A. H. Younan ◽  
J. M. Hamilton ◽  
J. Weaver
Keyword(s):  
Traditional Approach ◽  
Relative Strength ◽  
First Year ◽  
Burial Depth ◽  
Buried Pipe ◽  
Element Analysis ◽  
Statistical Characterization ◽  
The Impact ◽  
Adequate Reliability

Offshore arctic pipelines must be designed with adequate reliability against damage or rupture due to the effects of ice features that gouge the seafloor. A common design approach is to bury the pipeline sufficiently deep to avoid contact by a gouging ice keel of a target rare return interval. The effects of sub-gouge soil displacements on pipe stress or strain are also assessed. It is implicitly assumed, in this traditional approach, that ice keels have infinite strength and momentum, so that gouge depths are not limited by ice keel failure and direct contact of ice on pipe results in rupture. However, many first-year ice features may not be strong enough to gouge the soil to the extreme gouge depths. Considering the high cost of incremental pipeline burial depth, it may be desirable to account for limits imposed on extreme gouge depth by soil resistance. Introducing these limits, however, gives rise to additional uncertainty and requires the development of a reliability framework to assess the consequences of direct ice contact on the buried pipe. This paper presents a methodology for evaluating the probability of ice gouging non-performance of a pipeline while explicitly accounting for the ability of the seabed soil to limit ice gouge depth based on the relative strength of soil and ice keel. Non-performance is defined either as ice contact on the pipe or exceedence of some level of acceptable pipe strain when contacted by ice. A three-step approach is followed through the use of nonlinear finite element analysis to estimate pipeline capacity, the statistical characterization of demand from ice gouging events, and the development of a reliability framework combining demand and capacity. Parameters governing the capacity of the pipeline are identified, the sensitivity of the pipeline reliability to various parameters is investigated, and the impact of allowing ice contact on pipeline reliability is presented. Relative merits and risks of allowing ice contact are discussed in the context of pipeline reliability. The presented results and discussions are believed to be of significant help in the development of burial depth criteria for future offshore arctic pipelines, and certainly in the reassessment of existing ones.

Sign in / Sign up

Export Citation Format

Share Document