Dynamic analysis of steel frames with uncertain semi-rigid connections

The paper addresses the dynamic analysis of linear steel frames with uncertain semi-rigid connections subjected to deterministic seismic excitation. The uncertainty is conveniently characterised in the reduced modal space using a recently proposed surrogate model, which requires only a reduced set of parameters. A procedure is presented in which the model parameters are identified over various configurations calibrating the probabilistic definition in the full geometrical space. It is found that the dynamic response can significantly be influenced by the level of connection flexibility and its random fluctuations around the nominal value. Comparisons with conventional analyses and Monte Carlo simulations evidence that the proposed model is an efficient alternative for accurately representing the response of structures with uncertainties.