This study focuses on numerical finite element modelling of the global mechanical behaviour of circular hollow section columns with steel fibre-reinforced concrete infill at elevated temperatures. The three-dimensional numerical model was designed using ATENA software. The fracture-plastic material model was used to simulate the exact behaviour of the steel fibre-reinforced concrete (SFRC) in compression and tension. Work includes data from experimental studies in the vertical furnace, development of the SFRC material model, description of the global thermal and mechanical model, validation of the model, and a sensitivity study of the main parameters. The sensitivity study shows definite improvements in columns fire resistance by implementing the SFRC unique properties. The model is recommended to be used for the further parametric study and preparation of an analytical model for columns with steel fibre-reinforced concrete infill as per the European standard for composite member design in the fire in prEN1994-1-2:2020.

本研究侧重于钢纤维混凝土填充圆形空心截面柱在高温下的整体力学行为的数值有限元建模。三维数值模型是使用ATENA软件设计的。断裂塑性材料模型用于模拟钢纤维混凝土 (SFRC) 在压缩和拉伸中的精确行为。工作包括来自立式炉实验研究的数据、SFRC 材料模型的开发、全局热和机械模型的描述、模型的验证以及主要参数的敏感性研究。敏感性研究表明，通过实施 SFRC 独特的特性，柱的耐火性得到了明显的改善。