Hybrid fire testing enables the evaluation of structural elements under realistic fire-induced boundary conditions by coupling physical specimens subjected to fire with numerical models. Although previous hybrid fire tests have demonstrated feasibility in single-degree-of-freedom (SDOF) configurations, extension to multi-degree-of-freedom (MDOF) scenarios remains challenging due to control instability and the complex interaction between mechanical and thermal deformations. This study presents the development and validation of a novel methodology for conducting MDOF hybrid fire testing of beam elements. The proposed method employs a model-based adaptive kinematic transformation control scheme, implemented using the University of Toronto’s Simulation (UT-SIM) hybrid simulation framework, and was tested in a small-scale setup that replicates full-scale boundary conditions. A series of tests was conducted using both conventional and adaptive control strategies. Results demonstrate that the adaptive control significantly improves the ability to maintain stability under thermal loading. The hybrid fire test results closely matched standalone numerical simulations and captured the influence of structural restraint on thermomechanical response, highlighting the method’s potential to support performance-based fire design with enhanced realism and control stability.
Ma et al. (Tue,) studied this question.