The Experts below are selected from a list of 26943 Experts worldwide ranked by ideXlab platform
Torgeir Moan - One of the best experts on this subject based on the ideXlab platform.
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life cycle structural integrity management of Offshore Structures
Structure and Infrastructure Engineering, 2018Co-Authors: Torgeir MoanAbstract:An overview of structural integrity management of Offshore Structures in the oil and gas energy sector is presented in this article. Based on relevant experiences with the hazards, accidents and me...
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Reliability of aged Offshore Structures
Condition Assessment of Aged Structures, 2008Co-Authors: Torgeir MoanAbstract:This chapter deals with methods for reliability analysis of Offshore Structures subjected to strength degradation due to crack growth and corrosion. It is shown how the effect of inspection and repair on the reliability level can be accounted for. Methods for reliability assessment of both component and simple systems are considered. Moreover, it is discussed how this methodology can be applied in making decisions about design as well as inspection and repair.
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reliability based management of inspection maintenance and repair of Offshore Structures
Structure and Infrastructure Engineering, 2005Co-Authors: Torgeir MoanAbstract:Development of reliability-based management of inspection, monitoring, maintenance and repair (IMMR) of various types of Offshore Structures is described, with a focus on management of hull damage due to crack growth and corrosion. Operational experiences with respect to degradation of various types of Offshore Structures are summarized. The interrelation between design criteria and IMMR is emphasized. Explicit design for robustness in terms of an accidental collapse limit state and monitoring by the use of the leak before break principle to identify damage are highlighted. It is shown how design for robustness, choice of inspection method and scheduling as well as repair strategy, need to be implemented to obtain an acceptable risk for various types of Offshore Structures. Finally, the particular features of reliability based structural reassessment for extension of the service life, are briefly outlined and exemplified.
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Implications of Inspection Updating on System Fatigue Reliability of Offshore Structures
Journal of Offshore Mechanics and Arctic Engineering, 2000Co-Authors: Torgeir Moan, Ruxin SongAbstract:Offshore Structures are considered as fail safe and inspections are carried out during their service lifetime to assess their actual condition. In this paper, the effect of inspection updating on fatigue reliability of Offshore Structures is investigated. In particular, the effect of inspection on the reliability of both inspected and uninspected joints is assessed dependent upon the correlation of properties of different joints. The effect of repeated inspections and inspection sample size on fatigue reliability is also investigated. The influence of inspection of certain joints on the reliability of a series system is studied and the effect of system-based updating policy on fatigue reliability is investigated. It is found that the system reliability is significantly affected by the inspection updating policy. [S0892-7219(00)00403-9]
Ruxin Song - One of the best experts on this subject based on the ideXlab platform.
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Implications of Inspection Updating on System Fatigue Reliability of Offshore Structures
Journal of Offshore Mechanics and Arctic Engineering, 2000Co-Authors: Torgeir Moan, Ruxin SongAbstract:Offshore Structures are considered as fail safe and inspections are carried out during their service lifetime to assess their actual condition. In this paper, the effect of inspection updating on fatigue reliability of Offshore Structures is investigated. In particular, the effect of inspection on the reliability of both inspected and uninspected joints is assessed dependent upon the correlation of properties of different joints. The effect of repeated inspections and inspection sample size on fatigue reliability is also investigated. The influence of inspection of certain joints on the reliability of a series system is studied and the effect of system-based updating policy on fatigue reliability is investigated. It is found that the system reliability is significantly affected by the inspection updating policy. [S0892-7219(00)00403-9]
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Reliability-based assessment of Offshore Structures at cold phase considering the effect of inspection
1999Co-Authors: Ruxin Song, Peng Peng ZhengAbstract:After ending their service lifetime, Offshore Structures will be decommissioned and subject to decision of removal/final disposal. At this cold phase, it is required that the Structures shall still maintain the minimum safety requirement for removable. How to minimize the total maintenance costs of Offshore Structures at cold phase is the concern of operators. In this paper, a methodology is presented on assessment of Offshore Structures at cold phase considering the effect of inspection based on system reliability method. The effect of inspection updating on the assessment of Offshore Structures is investigated systematically. In particular, the effect of inspection on the reliability of both inspected and un-inspected joints is assessed. The influence of inspection of certain joints on the system reliability is studied and the effect of system-based updating policy on fatigue reliability is investigated. A numerical example is given to demonstrate the use of proposed method to assess Offshore Structures at cold phase efficiently and economically. It is believed that the maintenance costs could be reduced significantly by applying the proposed methodology.
Jasmine Siu Lee Lam - One of the best experts on this subject based on the ideXlab platform.
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Reliability analysis of Offshore Structures within a time varying environment
Stochastic Environmental Research and Risk Assessment, 2015Co-Authors: Yi Zhang, Jasmine Siu Lee LamAbstract:The analysis and design of Offshore Structures necessitates the consideration of environmental loads. Realistic modeling of the environmental loads is particularly important to ensure reliable performance of these Structures. In this paper, structural reliability analysis of Offshore Structures subjected to a time varying environment is investigated. In this work, an extreme value statistical model for the wave height is adopted as a basis for the performance assessment of a jacket structure. Due to the changing environment, the model parameters are modeled to be time varying. To deal with this issue, two segmentation algorithms are proposed and applied to the observed data in order to derive piecewise stationary processes for a statistical analysis. The investigation includes the extreme value modeling of the wave height in the characterization of the sea load. The implementation of the segmentation algorithms in the original data eventually leads to approximations of the safety quality of the existing structure within different time interval. The computed result is developed to reflect the time varying effects in the failure probability of Structures. The results are compared with the traditional extreme values approach in view of the accuracy and information content. The investigation is also extended to a case where the design of the structure ignores the time varying property.
Yonghwan Kim - One of the best experts on this subject based on the ideXlab platform.
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Panel generation framework for seakeeping analysis of multiple bodies and Offshore Structures
Engineering with Computers, 2015Co-Authors: Kwang Hee Ko, Min-guk Seo, Kyong-hwan Kim, Jongho Lee, Yonghwan KimAbstract:This paper presents a panel generation framework for seakeeping analysis of multiple bodies and Offshore Structures. The configurations of multiple bodies and Offshore Structures are different from those of a single ship. In particular, the topological structure of the free surfaces becomes complicated due to the multiple floating bodies, resulting in multiple classifications for the free surfaces based on their genus. The multi-body configuration consists of two floating bodies placed in two configurations, i.e., side by side and tandem, which would generate two holes in the free surface. For the Offshore structure case, multiple holes are generated in the free-surface domain due to the legs of the Offshore structure. In this work, strategies for generating body and free-surface panels are provided, and the results are analyzed. A software prototype that implements the proposed methods is developed to provide efficient panel generation for multiple bodies and Offshore Structures. Examples demonstrate that the proposed framework can be successfully used for seakeeping analysis of multiple bodies and Offshore Structures.
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Panel generation framework for seakeeping analysis of multiple bodies and Offshore Structures
Engineering with Computers, 2015Co-Authors: Kwang Hee Ko, Min-guk Seo, Kyong-hwan Kim, Jongho Lee, Yonghwan KimAbstract:This paper presents a panel generation framework for seakeeping analysis of multiple bodies and Offshore Structures. The configurations of multiple bodies and Offshore Structures are different from those of a single ship. In particular, the topological structure of the free surfaces becomes complicated due to the multiple floating bodies, resulting in multiple classifications for the free surfaces based on their genus. The multi-body configuration consists of two floating bodies placed in two configurations, i.e., side by side and tandem, which would generate two holes in the free surface. For the Offshore structure case, multiple holes are generated in the free-surface domain due to the legs of the Offshore structure. In this work, strategies for generating body and free-surface panels are provided, and the results are analyzed. A software prototype that implements the proposed methods is developed to provide efficient panel generation for multiple bodies and Offshore Structures. Examples demonstrate that the proposed framework can be successfully used for seakeeping analysis of multiple bodies and Offshore Structures.
Yi Zhang - One of the best experts on this subject based on the ideXlab platform.
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Reliability analysis of Offshore Structures within a time varying environment
Stochastic Environmental Research and Risk Assessment, 2015Co-Authors: Yi Zhang, Jasmine Siu Lee LamAbstract:The analysis and design of Offshore Structures necessitates the consideration of environmental loads. Realistic modeling of the environmental loads is particularly important to ensure reliable performance of these Structures. In this paper, structural reliability analysis of Offshore Structures subjected to a time varying environment is investigated. In this work, an extreme value statistical model for the wave height is adopted as a basis for the performance assessment of a jacket structure. Due to the changing environment, the model parameters are modeled to be time varying. To deal with this issue, two segmentation algorithms are proposed and applied to the observed data in order to derive piecewise stationary processes for a statistical analysis. The investigation includes the extreme value modeling of the wave height in the characterization of the sea load. The implementation of the segmentation algorithms in the original data eventually leads to approximations of the safety quality of the existing structure within different time interval. The computed result is developed to reflect the time varying effects in the failure probability of Structures. The results are compared with the traditional extreme values approach in view of the accuracy and information content. The investigation is also extended to a case where the design of the structure ignores the time varying property.
