Nuanced Robustness Analysis with Limited Information: Fid-Bau Portal

Nuanced Robustness Analysis with Limited Information

Zhang, M. Q. / Beer, M. / Koh, C. G. / Jensen, H. A.

This paper presents a nuanced robustness analysis for structures when only limited information is available. A new methodology based on fuzzy set theory is proposed to cope with scarce information as a major problem in the performance assessment of existing structures. The developed robustness measure provides information on the relationship between structural robustness and the magnitude of uncertainty in the damage of the structure. This feature is enabled through a nuanced consideration of imprecision in the damage assessment through alpha-level discretization. An entropy-based robustness measure is formulated as a function of imprecision in the damage state. On this basis, different design solutions can be compared in a one-swoop analysis with respect to their robustness for different magnitudes of damage. Furthermore, this approach can be used to assess the effort for inspection versus gain in precision of the predicted structural performance. The development is of a general nature. In this paper, it is elucidated in the context of a typical offshore engineering problem to demonstrate its application in practical cases. Fixed offshore platforms with different brace configurations are compared in light of robustness with respect to damage from corrosion.