TY - EJOU AU - Wang, Wei AU - Shen, Yudong AU - Zhu, Ruitang AU - Wang, Guangyong TI - Fire Resistance Calculation Model for Steel-Reinforced Concrete Frame Structures T2 - Structural Durability \& Health Monitoring PY - VL - IS - SN - 1930-2991 AB - Frame structures with steel-reinforced concrete (SRC) columns and reinforced concrete (RC) beams are widely used in high-rise buildings, which are susceptible to significant fire hazards. Therefore, analyzing and designing the fire resistance of such SRC-RC frame structures (hereinafter referred to as SRC frame structures) is critical. Developing an effective calculation model for fire resistance is essential, as it provides a robust tool for assessing fire response and facilitating fire-resistant design. In this study, a fire resistance calculation model for SRC frame structures was developed using sequential thermal-mechanical coupling, with carefully selected thermal parameters and material constitutive models. The model was further refined by appropriately determining element types, boundary conditions, and numerical solution methods. Using the proposed model, the temperature distribution and deformation in fire resistance tests of SRC frame structures were numerically simulated. The calculated results agree well with experimental data, validating the accuracy and reliability of the proposed model for analyzing the fire resistance performance of SRC frame structures. Based on this validated model, a systematic analysis of fire resistance was conducted, revealing the failure mechanisms and internal force redistribution of SRC frame structures under fire conditions. The results indicate that in the early stage of a fire, thermal expansion induces axial compression in the beams, thereby reducing bending moments at both beam ends and the mid-span. In the later stage, as beam deflection increases, the axial compression induced by thermal expansion gradually diminishes and eventually disappears. KW - Fire resistance; calculation model; steel-reinforced concrete; frame structures; sequential thermal-mechanical coupling DO - 10.32604/sdhm.2026.084151