Design loads and reliability assessment of marine structures considering statistical models of metocean data

2021 ◽  
Vol 241 ◽  
pp. 110099
Author(s):  
Yuliang Zhao ◽  
Sheng Dong
2019 ◽  
Vol 7 (11) ◽  
pp. 400 ◽  
Author(s):  
Fazeres-Ferradosa ◽  
Taveira-Pinto ◽  
Rosa-Santos ◽  
Chambel

The present paper provides a reliability assessment of scour protections applicable to both the static and dynamic stability design. As a case study, Horns Rev 3 hindcast data is used to simulate different failure criteria for an exemplary scour protection suitable for an offshore monopile foundation. The results show that the probability of failure is influenced by several factors, namely the wave friction factor, the definition of the acceptable damage number or the formulations used to calculate the bed shear-stress. The reliability assessment also indicates that annual probabilities of failure, associated to each criterion, might be comparable with the values presented in reliability standards for marine structures. Based on the results, this paper highlights future recommendations to improve the reliability-based design and analysis of scour protections for offshore foundations.


Author(s):  
Miguel Ángel Navas Álvarez ◽  
José Carpio Ibáñez ◽  
Carlos Sancho de Mingo

The statistical nature of failures in repairable systems does not have a behaviour similar to non-repairable systems. The statistical models developed for the study of the reliability of repairable systems mostly based on the application of stochastic processes. However, there is a group of prediction models for reliability based on time series analysis. Below are the results and conclusions of the application of simple regression models in the escalators Avante model (TNE), in order to assess their potential use by maintenance organizations.


Author(s):  
Andreas F. Haselsteiner ◽  
Ryan G. Coe ◽  
Lance Manuel ◽  
Phong T. T. Nguyen ◽  
Nevin Martin ◽  
...  

Abstract A wide range of methods have been proposed for the derivation of environmental contours for marine structures that must meet reliability targets. An environmental contour is a set of joint extremes of environmental conditions associated with a target return period. In general, environmental contour methods help with the prediction of some future critical combinations of environmental conditions (e.g., wind, waves, current) at a location of interest based on a limited dataset, thus allowing designers to ensure a prescribed structural reliability. In fact, some of these contour methods are specifically recommended by technical specifications and standards as part of a design process. This paper outlines the rules and procedures for a collaborative benchmarking exercise — focused on open comparison — in which researchers are invited to develop and present their own contour derivation approaches based on common datasets that will be available to all. Hindcast and observational datasets are considered and two exercises are planned: One focuses on applying environmental contour methods to a wide range of datasets and the other focuses on uncertainty characterization. Besides describing the benchmark’s methodology, this paper presents baseline results of computed contours following current recommendations. The overall goals of this endeavor are: (i) to work towards the development of more robust statistical models and contour construction methods, (ii) to encourage increased discussion in the international research community and among practitioners, and (iii) to support ongoing efforts to improve technical specifications and standards.


Author(s):  
Alberto C. Morandi

This review paper is a part of the Douglas Faulkner Symposium within OMAE 2006. It is structured along the following main topics: a) the potential for combining advanced numerical modeling of structures with structural reliability techniques, b) the need for better understanding the risks associated with abnormal environmental events and their potential impact on marine structures, particularly for offshore operations in the Gulf of Mexico. These are fields where Professor Faulkner’s pioneering efforts continue to be very relevant and an inspiration for future academic and industry research.


Author(s):  
Bernt J. Leira ◽  
Dag Myrhaug ◽  
Ha˚vard Holm

A bivariate Gumbel distribution is established based on transformation of an existing bivariate Rayleigh distribution. Application of this distribution in relation to reliability assessment of marine structures is subsequently addressed. Linear combinations of the two basic variables which are Gumbel distributed are further considered. The role of the Gumbel distribution in connection with reliability assessment of marine structures is discussed. Comparison with another class of bivariate Gumbel distributions (Gumbel Type A) is also made.


2021 ◽  
Vol 247 ◽  
pp. 01073
Author(s):  
Sergey A. Solovyev ◽  
Anastasia A. Solovyeva

Trusses are common structural elements in many industrial and civil buildings. The article describes the approach to planar trusses reliability analysis in case of limited statistical data. The proposed approach can be used when it is complicated to determine a cumulative distribution function for design loads and physical/mechanical properties of the material of structural elements. The proposed method for structural reliability analysis requires only estimates of mathematical expectations and standard deviations. The article also presents the equation for planar truss reliability assessment as a system of structural elements. The result of a planar truss reliability analysis is obtained at an interval of non-failure probabilities. If the resulting reliability interval is too wide for decision-making, it is necessary to improve the quality of statistical data for a more accurate assessment of reliability (non-failure probability).


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