Seismic Fragility of FRC Columns using Incremental Dynamic Analysis and eXtended Finite Element Method

Ensuring seismic resilience in earthquake-prone regions is imperative for structural safety. Fiber-Reinforced Concrete (FRC) columns hold promise for enhancing structural performance under seismic conditions. This study seeks to comprehensively evaluate their seismic behavior. The primary objective of this research is to assess and compare the seismic performance of various FRC column types, including polypropylene fibers (PFRC), steel fibers (SFRC), and hybrid combinations (HyFRC), in contrast to conventional reinforced concrete (RC) columns. To achieve this, the study employs eXtended Finite Element Method combined with Concrete Damage Plasticity (XFEM-CDP) in Abaqus to scrutinize static and dynamic responses. The nonlinear static pushover analysis unveiled a notable improvement in seismic resistance across all FRC types when compared to RC columns. Incremental dynamic analyses (IDA) are conducted using the selected suite of 10 near fault as-recorded ground motions to evaluate the inelastic seismic responses of different FRC bridge columns. XFEM-CDP simulations in Abaqus captured multiple aspects of FRC columns, such as concrete cracking, loss of stiffness and plastic behavior. Seismic fragility analysis of these FRC columns is conducted considering four damage states: a) longitudinal steel yielding, b) core concrete crushing, c) steel bar buckling, and d) longitudinal steel bar fracture. The results indicated that HyFRC columns exhibit the lowest damage vulnerability compared to PFRC and SFRC variants.