Simplified fiber beam-column model for inelastic analysis of moment-resisting steel frames

Conventional fiber beam-column models require monitoring the responses of many sections along the element length to account for the speared of inelasticity. Recently, a simplified approach that utilizes predefined flexibility-distribution functions to account for the spreading of inelasticity along the element length is introduced. The new approach is much simpler than the conventional fiber models as it does not require monitoring the responses of many sections along the element length, which results in a significant reduction in computations. The main shortcoming of this simplified approach is the need to estimate empirically a cross-section-shape dependent flexibility distribution factor by calibration with exact analysis. This study proposes a simplified model with flexibility-distribution functions that does not require any calibration with exact analysis. In this proposed model, the flexibility distribution factor is automatically calculated during the analysis without any user interference. The results of the numerical analysis carried out in this study on the one-element level and on the structure level indicate the effectiveness of the proposed model. (C) 2018 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).