AN APPROACH FOR TIME-DEPENDENT RELIABILITY ANALYSIS OF JACKUP STRUCTURES

Abstract

This paper proposes an approach for evaluation of time dependent reliability of Jackup
structures. An approach for signal processing using prolate spheroidal wave functions is
combined with stochastic field representation method to represent ocean waves with least
number of independent sources of uncertainty. First passage probability for dynamical systems
subject to stochastic loading was then used in the formulation of the reliability approach. A
simplified Jackup was modelled and used to demonstrate the time dependent reliability approach
by propagating the uncertain wave load on the unit. In-house computer codes were developed
for the analysis of the stochastic response in time-domain to obtain time dependent failure
probabilities. The results were compared with those of a similar model in which the statistical
method is used.