Comparison of Nonlinear Methods in the Seismic Evaluation of Reinforced Concrete Frames and Their Applicability in the Construction of Fragility Curves

Maraví V.H.; Paitán D.F.M.; Montesinos J.F.P. · SSRG International Journal of Civil Engineering (2026) · DOI: 10.14445/23488352/ijce-v13i5p124

Resumen

Conventional seismic analysis based on elastic approaches presents limitations in realistically capturing structural response under severe events, which has driven the development of nonlinear methodologies that allow for a more accurate characterization of building performance. In this context, this study aims to make a systematic comparison between the nonlinear static and nonlinear dynamic analyses in reinforced concrete frames, with the goals of identifying any divergences in the prediction of parameter performances and then assessing their applicability as input data for methodologies oriented towards fragility. The ETABS software was used to model a four-story building, and nonlinearity was incorporated through the use of plastic hinges according to ASCE41-17 and NIST GCR 10-917-5, and the characterization of the materials followed the LATBSDC 2020 norm. The evaluation of the behavior was based on the overturning moment and the base shear, while also considering gravitational loads and a scaled record of real earthquakes. The results acquired from the evaluations indicated that the nonlinear dynamic analysis estimated that the base shear and overturning moment values are approximately 18% and 16% higher, respectively, than those obtained with nonlinear static analysis. These results highlight the great ability of nonlinear dynamic analysis to capture transient effects and global instability phenomena. These outcomes allow us to argue that both methods provide useful information for structural performance evaluation, with the dynamic analysis more suitable for probabilistic studies, while static analysis constitutes a simplified and less computationally demanding alternative in preliminary design stages. Considering the limitation, this study was restricted to the analysis of a regular two-dimensional frame and a single seismic record; therefore, an extension to three-dimensional and irregular models accompanied by multiple ground motions is recommended to strengthen the generalization of the results.

Instituciones: Universidad Continental