Development of a Coupled CFD-FEA Model for Whole Building Fire Performance Determination

Abstract

The structural integrity of building products and their capacity to resist fire have become an increasing focus over recent decades. This thesis develops and evaluates a two-way coupled CFD–FEA framework to advance the understanding of fire–structure interactions in whole-building environments, with specific application to Tata Steel UK’s cladding systems. The Fire Dynamics Simulator (FDS) was employed to model fire be-haviour, while Abaqus was used for heat transfer and structural response. An existing FDS-to-Abaqus framework was extended to incorporate structural deformation, buckling, and nodal interpolation, supported by the implementation of a cut-cell Immersed Boundary Method. The framework was verified against BS 476-22 standard fire resistance tests, demonstrating its ability to reproduce key thermal and mechanical responses of insulated steel sandwich panels under fire exposure. The results highlight the capacity of the framework to capture deformation-driven fire propagation mechanisms that are not represented in conventional one-way models. However, simulations remain computationally expensive, limiting validation and scalability to large assemblies. To address this, potential strategies such as reduced-order modelling and parallelisation are identified. Overall, this work represents one of the first demonstrations of a fully integrated CFD–FEA coupling applied to cladding systems, providing a foundation for predictive fire performance assessment and contributing to the development of safer, more sustainable building products.