Assessment of model uncertainties for structural resistance

Uncertainties in resistance models play a significant role in the reliability analysis of structures and code calibration of partial factors for semi-probabilistic design. In spite of this importance, existing knowledge concerning model uncertainties and their characteristics seems to suffer from imprecise definitions and lack of available experimental data. Currently used probabilistic models and derived factors for model uncertainties are mostly based on intuitive judgements and limited data. This often leads to an unrealistic description of model uncertainties. The present study attempts to improve definitions of model uncertainties and proposes a general methodology for their quantification by comparing experimental and model results. It appears that model uncertainty should be always related to a specific model and scope of its application. The proposed approach seems to offer better understanding of model uncertainties and enables the specification of their real characteristics. (C) 2015 Elsevier Ltd. All rights reserved.