Modification of finite element models based on support vector machines for reinforced concrete beam vibrational analyses at elevated temperatures

摘要

To obtain accurate finite element models of reinforced concrete beams for vibrational analyses at elevated temperatures, a multivariate stepwise finite element model (FEM) updating strategy based on a support vector machine is proposed herein. This strategy considers the effects of simultaneous corrections of multiple physical parameters. First, based on the proposed updating strategy, the initial FEM of a simply supported beam was updated with special consideration given to the boundary conditions. Then, vibrational analyses of the simply supported beams at elevated temperatures were carried out through numerical simulations and experiments, and the attenuation response of the modal information was obtained. A comparison between the actual measured structural response and the modified model response shows that the proposed updating method is of practical engineering importance. This study presents a model updating method and the attenuation response of modal information during fire exposure, which lays a foundation for further research on the damage development of a reinforced concrete beam subjected to fire.