This work presents a simple and efficient framework for the fatigue reliability assessment of a vertical top-tensioned rigid riser. The fatigue damage response is considered as a narrow-band Gaussian stationary random process with a zero mean for the short-term behavior of a riser. Non-linearity in a response associated with Morison-type wave loading is accounted for by using a factor, which is the ratio of expected damage according to a non-linear probability distribution to the expected damage according to a linear method of analysis. Long-term non-stationary response is obtained by summing up a large number of short-term stationary responses. Uncertainties associated with both the strength and stress parts of the limit state function are quantified by a lognormal distribution. A closed form reliability analysis is carried out, which is based on the limit state function formulated in terms of Miner's cumulative damage rule. The results thus obtained are compared with the well-documented lognormal format of reliability analysis based on time to fatigue failure. The validity of using the lognormal hazard rate function in predicting the fatigue life is discussed. A Monte Carlo simulation technique is also used as a reliability assessment method. A simple algorithm is used to reduce the uncertainty associated with direct sampling at small probability of failure values and a small number of simulations. Simulation results are compared with closed form solutions. A worked example is included to show the practical riser design problem based on reliability analysis. © Springer-Verlag 2007.

Item Type:	Refereed Article
Keywords:	Failure analysis of riser; Fatigue analysis; Reliability analysis of riser; Wave loading; Deep water rigid marine riser; Reliability assessment method; Computer simulation; Failure (mechanical); Fatigue of materials; Monte Carlo methods; algorithm
Research Division:	Engineering
Research Group:	Maritime Engineering
Research Field:	Ocean Engineering
Objective Division:	Mineral Resources (excl. Energy Resources)
Objective Group:	Environmentally Sustainable Mineral Resource Activities
Objective Field:	Environmentally Sustainable Mineral Resource Activities not elsewhere classified
Author:	Khan, FI (Professor Faisal Khan)
ID Code:	94468
Year Published:	2008
Web of Science® Times Cited:	15
Deposited By:	NC Maritime Engineering and Hydrodynamics
Deposited On:	2014-09-09
Last Modified:	2014-09-09
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