TY - GEN

T1 - A new approach for robustness assessment of fixed offshore structures under imprecise marine corrosion

AU - Zhang, M. Q.

AU - Beer, M.

AU - Koh, C. G.

AU - Hirokane, M.

PY - 2011

Y1 - 2011

N2 - This paper presents a new approach for the robustness assessment of fixed offshore platforms under limited information. The effects of marine corrosion on the robustness of aging offshore structures is investigated. Due to scarce and imprecise information associated with the corrosion process, the amount of damage caused by the deterioration to the structural members cannot be specified precisely. Therefore, fuzzy variables are utilized to cater for the subjective character of the assessment of deterioration, which leads to an uncertain damage modeling. In this study, robustness refers to a high degree of independence between the uncertainty of the damage due to imprecise marine corrosion and the associated uncertainty in the structural safety. Robustness assessment based on an entropy measure is taken as the basis. While existing entropy-based robustness measures can provide a global view of structural robustness, the proposed methodology aims to scrutinize the structural robustness at various membership levels with respect to various degree of imprecision in uncertain damage. It is shown that this utilization of alpha-level discretization in the computation of an entropy-based robustness measure leads to improvements including a better correspondence with the intuitive understanding of uncertainty and robustness. The usefulness of the proposed method is demonstrated by way of investigations on fixed offshore platforms with different brace configurations.

AB - This paper presents a new approach for the robustness assessment of fixed offshore platforms under limited information. The effects of marine corrosion on the robustness of aging offshore structures is investigated. Due to scarce and imprecise information associated with the corrosion process, the amount of damage caused by the deterioration to the structural members cannot be specified precisely. Therefore, fuzzy variables are utilized to cater for the subjective character of the assessment of deterioration, which leads to an uncertain damage modeling. In this study, robustness refers to a high degree of independence between the uncertainty of the damage due to imprecise marine corrosion and the associated uncertainty in the structural safety. Robustness assessment based on an entropy measure is taken as the basis. While existing entropy-based robustness measures can provide a global view of structural robustness, the proposed methodology aims to scrutinize the structural robustness at various membership levels with respect to various degree of imprecision in uncertain damage. It is shown that this utilization of alpha-level discretization in the computation of an entropy-based robustness measure leads to improvements including a better correspondence with the intuitive understanding of uncertainty and robustness. The usefulness of the proposed method is demonstrated by way of investigations on fixed offshore platforms with different brace configurations.

KW - Alpha-level discretization

KW - Entropy measure

KW - Imprecision

KW - Marine corrosion

KW - Robustness assessment

UR - http://www.scopus.com/inward/record.url?scp=84876946815&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84876946815

T3 - Proceedings of the 8th International Conference on Structural Dynamics, EURODYN 2011

SP - 2919

EP - 2926

BT - Proceedings of the 8th International Conference on Structural Dynamics, EURODYN 2011

A2 - Lombaert, G.

A2 - Muller, G.

A2 - De Roeck, G.

A2 - Degrande, G.

T2 - 8th International Conference on Structural Dynamics, EURODYN 2011

Y2 - 4 July 2011 through 6 July 2011

ER -