Research on fiber models of SRC component beam segments using the discrete element method

Accurately predicting the elasto-plastic behavior of Steel-Reinforced Concrete (SRC) components is crucial for seismic safety assessments and even collapse performance studies of buildings with such components. To enable the simulation of the entire collapse process of SRC structural buildings using the discrete element method (DEM), the steel fiber bundles have been introduced in this paper based on the segment fiber model of DEM, and the segment fiber model of SRC components (SRC-SFM) has been constructed. The internal steel and reinforcement fiber bundles have been modeled using a uniaxial steel constitutive model, while the concrete fiber bundles have been modeled using a uniaxial concrete constitutive model that takes into account the confinement effects of the steel and stirrups. The SRC-SFM has been integrated into the discrete element computational program DEM-Collapse for building structural collapse analysis, enabling it to perform mechanical performance analysis of SRC components. Through this method, the hysteretic performance of six H-shaped steel SRC test components under low-cycle repeated loading with different material parameters and axial compression ratios was simulated and analyzed to validate the reasonability of using the SRC-SFM for mechanical performance analysis of SRC components. The results show that the simulated curves from the SRC-SFM agree well with the experimental curves in terms of peak load-carrying capacity, curve shape, and stiffness degradation. The established SRC-SFM in this paper lays a solid foundation for future analysis of the entire collapse process of SRC building structures.