Resistance model uncertainty in non-linear finite element analyses of cyclically loaded reinforced concrete systems

This study assesses the partial safety factor corresponding to the resistance model uncertainties in the use of non-linear finite element analyses (NLFEAs) for reinforced concrete systems subjected to cyclic loads. Specifically, various walls experimentally tested are considered for this investigation and are simulated through two-dimensional (i.e., plane stress) finite element (NLFE) models. The comparison between the global resistances from the plane stress NLFE structural models and the experimental tests is carried out considering the possible modelling hypotheses available in relation to the mechanical response of reinforced concrete structural systems subjected to cyclic loads. After that, a probabilistic processing of the abovementioned epistemic uncertainties is carried out in line with a Bayesian updating. In detail, each prior distribution of the resistance model uncertainty related to a specific combination of the modelling hypotheses is computed and successively updated with the data achieved from the other models to estimate the posterior distribution. Hence, the coefficient of variation and the mean value of the resistance model uncertainties are evaluated and the corresponding partial safety factor is assessed in line with the NLFEA safety formats of reinforced concrete systems for seismic analyses.