A New Approach for Dynamic Reliability Analysis of Offshore Platforms

Volume 2: Safety and Reliability; Pipeline Technology ◽

10.1115/omae2003-37046 ◽

2003 ◽

Author(s):

Wei-Liang Jin

Keyword(s):

Reliability Analysis ◽

Failure Criterion ◽

Offshore Platform ◽

Seismic Action ◽

Offshore Platforms ◽

Structural Dynamic ◽

Jacket Platform ◽

Dynamic Reliability ◽

Strength Failure ◽

Offshore Jacket Platform

The theoretical framework of a new dynamic reliability analysis approach for offshore jacket platforms is constructed in this paper. In this approach, the structural dynamic reliability analysis integrates the structural dynamic response theory with the random sampling technique on stochastic variables of the platform. Offshore jacket platform is assumed as a shear type one and is controlled by its horizontal resistance bearing capacity. The failure criterion of offshore platform dynamic reliability includes two aspects: strength failure criterion and deformation failure criterion. The strength failure criterion is based on the double-damage criterion of ultimate dynamic analysis, while the deformation failure criterion depends on the requirement of the offshore oil production. The dynamic reliability formula of offshore platforms is gained on the basis of the first crossing theory. In this paper, uncertainties of offshore jacket platform dynamic reliability subjected to wave hydrodynamic and seismic action are studied respectively. The probabilistic distributions and its statistical characteristics of wave hydrodynamic and seismic action are given on the base of limit bearing state of the platform. The dynamic reliability analysis of an offshore platform W11-4C, located at the gulf of Weizhou, South China Sea, is carried out. Some valuable conclusions are summarized.

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Structural dynamic reliability analysis of super large-scale lattice domes during earthquakes using the stochastic finite element method

Soil Dynamics and Earthquake Engineering ◽

10.1016/j.soildyn.2021.107076 ◽

2021 ◽

pp. 107076

Author(s):

Huidong Zhang ◽

Ning An ◽

Xinqun Zhu

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Reliability Analysis ◽

Large Scale ◽

Stochastic Finite Element Method ◽

Stochastic Finite Element ◽

Structural Dynamic ◽

Dynamic Reliability ◽

Element Method

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System Reliability Analysis of an Offshore Jacket Platform

Journal of Ocean University of China ◽

10.1007/s11802-020-4181-2 ◽

2020 ◽

Vol 19 (1) ◽

pp. 47-59 ◽

Cited By ~ 3

Author(s):

Yuliang Zhao ◽

Sheng Dong ◽

Fengyuan Jiang ◽

Carlos Guedes Soares

Keyword(s):

Reliability Analysis ◽

System Reliability ◽

Jacket Platform ◽

Offshore Jacket Platform ◽

System Reliability Analysis

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Seismic Reliability Analysis of MDOF Systems Based on Odd Exponent Wavelet

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.1711 ◽

2011 ◽

Vol 194-196 ◽

pp. 1711-1715

Author(s):

Mei Ling Xiao ◽

Liao Yuan Ye ◽

Chun Tao Gao

Keyword(s):

Reliability Analysis ◽

Structural Response ◽

Maximum Probability ◽

Structural Dynamic ◽

Seismic Reliability ◽

Dynamic Reliability ◽

Mdof Systems ◽

First Passage Failure ◽

Duhamel Integral ◽

Primary Advantage

This study proposed non-failure or non-disabled probability of structure suffering random dynamic load within given time. A wavelet method based on its conception was proposed for seismic dynamic reliability analysis of MDOF system：From the Duhamel integral of the dynamic structural response, the structure stochastic response was expressed as earthquake ground motion’s wavelet transform. The ground motion and structure responses were modeled as non-stationary random process using odd exponent wavelets. The first-passage failure criterion and maximum probability were employed to estimate the structural dynamic reliability. The primary advantage of the proposed method is that it does not need to calculate spectral moments from the power density function integral, which are usually difficult to obtain the analytical expressions.

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Study of Offshore Jacket Platform Attached With Tuned Liquid Column Gas Damper

Volume 1: Offshore Technology ◽

10.1115/omae2017-62373 ◽

2017 ◽

Author(s):

P. Sathish ◽

A. S. Sajith

Keyword(s):

Natural Resources ◽

Wave Theory ◽

Wave Force ◽

Offshore Structures ◽

Liquid Column ◽

Offshore Platforms ◽

Jacket Platform ◽

Tuned Liquid Dampers ◽

Offshore Jacket Platform ◽

Gas Damper

With increase in need of energy, scarcity of natural resources also increases. Need for energy has led the people to move into the ocean since they contain abundant natural resources. Offshore platforms play a major role in exploring and exploiting these resources. Jacket platform being a fixed offshore jacket platform is used in water depths 300 to 400 m. The study of behavior of these offshore structures is vital part in the design since they are subjected to dynamic loading of waves, wind, earthquake, ice etc. These structures in hostile environment are subjected to heavy loads. There is need for controlling the response of these structures. This can be achieved by providing external dampers. There are various dampers available to control the response of structures. Tuned liquid dampers (TLD)s and Tuned Liquid Column Damper (TLCD)s use liquid inside to tune its frequency to natural frequency of structure. Tuned Liquid Column Gas Damper (TLCGD) is latest version of dampers. It has a unique flexibility of tuning frequency compared to all other dampers. In the present study, jacket platform is modeled as Multi degree of freedom (MDOF) system. At later stage, for simplistic analysis, MDOF system is reduced to SDOF system using static condensation. Performance of TLCGD for both the systems is compared. Airy’s wave theory is used for wave force excitation. Equations of motions for Jacket platform models attached with TLCGD are developed and solved using Newmarks β method in MATLAB. TLCGD is found to be very flexible in tuning the frequency and maximum reductions in response, 21.3% and 23.14% are observed at 0.3 MPa for MDOF and SDOF systems respectively. Work done shows that the results for MDOF and SDOF are comparable and hence, jacket as SDOF can be used for analysis for reducing the complexities.

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Weighted Regression-Based Extremum Response Surface Method for Structural Dynamic Fuzzy Reliability Analysis

Energies ◽

10.3390/en12091588 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1588 ◽

Cited By ~ 6

Author(s):

Cheng Lu ◽

Yun-Wen Feng ◽

Cheng-Wei Fei

Keyword(s):

Reliability Analysis ◽

Response Surface ◽

Response Surface Method ◽

Weighted Regression ◽

Fuzzy Reliability ◽

Safety Criterion ◽

Structural Dynamic ◽

Dynamic Reliability ◽

Surface Method ◽

Turbine Blisk

The parameters considered in structural dynamic reliability analysis have strong uncertainties during machinery operation, and affect analytical precision and efficiency. To improve structural dynamic fuzzy reliability analysis, we propose the weighted regression-based extremum response surface method (WR-ERSM) based on extremum response surface method (ERSM) and weighted regression (WR), by considering the randomness of design parameters and the fuzziness of the safety criterion. Therein, we utilize the ERSM to process the transient to improve computational efficiency, by transforming the random process of structural output response into a random variable. We employ the WR to find the efficient samples with larger weights to improve the calculative accuracy. The fuzziness of the safety criterion is regarded to improve computational precision in the WR-ERSM. The WR-ERSM is applied to perform the dynamic fuzzy reliability analysis of an aeroengine turbine blisk with the fluid-structure coupling technique, and is verified by the comparison of the Monte Carlo (MC) method, equivalent stochastic transformation method (ESTM) and ERSM, with the emphasis on model-fitting property and simulation performance. As revealed from this investigation, (1) the ERSM has the capacity of processing the transient of the structural dynamic reliability evaluation, and (2) the WR approach is able to improve modeling accuracy, and (3) regarding the fuzzy safety criterion is promising to improve the precision of structural dynamic fuzzy reliability evaluation, and (4) the change rule of turbine blisk structural stress from start to cruise for the aircraft is acquired with the maximum value of structural stress at t = 165 s and the reliability degree (Pr = 0.997) of turbine blisk. The proposed WR-ERSM can improve the efficiency and precision of structural dynamic reliability analysis. Therefore, the efforts of this study provide a promising method for structural dynamic reliability evaluation with respect to working processes.

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Integrated Probabilistic-Mechanistic Deterioration Modeling for Preventive Maintenance of Aging Fixed Offshore Jacket-Type Platforms

Volume 2B: Structures, Safety, and Reliability ◽

10.1115/omae2020-18927 ◽

2020 ◽

Author(s):

Ishwarya Srikanth ◽

M. Arockiasamy

Keyword(s):

Preventive Maintenance ◽

Probabilistic Approach ◽

Offshore Platform ◽

Mechanistic Modeling ◽

Residual Service Life ◽

Offshore Platforms ◽

Uniform Corrosion ◽

Jacket Platform ◽

Condition State ◽

The Impact

Abstract Most of the offshore platforms in the world are designed as steel jacket-type platforms for oil and gas exploration and production. A significant amount of research has been carried out over the past two decades to understand ageing and the associated degradation of offshore structural members. The paper proposes an approach for prioritization and preventive maintenance of jacket-type platform. Offshore platform maintenance systems are dependent on deterioration models to predict the future condition of structural elements. The input for these models consists of condition states of different jacket elements and their evolution as a function of time. One of the challenges includes lack of availability of condition state records for the aging platforms. This paper proposes a methodology for developing deterioration models when there is a scarcity of inspection records. This study focusses on developing a methodology for i) the impact ranking of different bracing member groups of the jacket platform and ii) deterioration models using integrated probabilistic-mechanistic modeling. Firstly, a typical jacket-type offshore platform under the North Sea conditions is modeled and analyzed under wave and current loads. Then, nonlinear static (pushover) analyses are performed for the undamaged jacket platform. The criticality of the different groups of bracing elements is obtained in terms of Residual Resistance Factor by carrying-out redundancy analyses. Soil-structure interaction effect is considered in the analyses and the results are compared with the hypothetical fixed-support end condition. The member groups are then ranked based on their impact on the ultimate strength of the jacket platform. Secondly, deterioration models for jacket legs and bracings in splash and immersion zones are obtained based on integrated mechanistic-probabilistic approach. An idealized uniform corrosion model is used in generating the member condition state probabilities. Condition state probabilities for jacket legs and bracings are then generated using Monte Carlo simulations. The residual service life of the jacket elements is predicted from the deterioration models which could be utilized for preventive maintenance of the jacket platform.

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