High-strength steel has been extensively used in numerous structures or high-rise buildings because of its high strength, ductility, and weldability. However, high-strength steel structures are vulnerable to fire hazards, so the ability to predict structural behavior is crucial in structural fire safety design. Creep behavior is one of the primary factors influencing the response of steel at high temperatures. This paper presents numerical studies using the fire dynamics simulator (FDS) and finite element method (FEM) coupling models to predict the structural behavior of a protected beam with a cavity for H-SA700 high-strength steel at elevated temperatures, including the creep effect. A comparison between simulation and experiment results demonstrates the validity of the process. In detail, based on a set of tensile tests conducted at six constant temperatures between 23°C and 600°C, the creep model is proposed. Subsequently, because creep is temperature-dependent, the heat transfer model used to predict the temperature distribution of the steel is developed. The effect of the partially damaged protection cover is discussed. Finally, it is found that with the temperature distribution from FDS-FEM integration and the proposed creep models, the collapse time of the beam can be defined. This study provides a practical approach for developing the creep model without creep tests and applying it to complex structures during fires.

高强度钢因其高强度、延展性和可焊性而被广泛应用于众多结构或高层建筑中。然而，高强度钢结构容易发生火灾，因此预测结构行为的能力在结构消防安全设计中至关重要。蠕变行为是影响钢在高温下响应的主要因素之一。本文介绍了使用火灾动力学模拟器 (FDS) 和有限元法 (FEM) 耦合模型来预测 H-SA700 高强度钢带空腔的受保护梁在高温下的结构行为的数值研究，包括蠕变效应。仿真与实验结果的比较证明了该过程的有效性。具体来说，基于在23°C至600°C之间的六个恒温下进行的一组拉伸试验，提出了蠕变模型。随后，由于蠕变与温度相关，因此开发了用于预测钢的温度分布的传热模型。讨论了部分损坏的保护罩的影响。最后，发现利用 FDS-FEM 集成的温度分布和所提出的蠕变模型，可以定义梁的倒塌时间。这项研究提供了一种无需蠕变测试即可开发蠕变模型并将其应用于火灾期间复杂结构的实用方法。