Advancing Fire–Structural Performance Assessment of Timber Structures with WoodST: Supporting Code and Standard Development and Product Innovation

As timber construction continues to expand toward taller and larger buildings, ensuring structural resilience under fire conditions requires advanced fire–structural performance assessment approaches. Such assessments generally integrate fire models to define thermal exposure, heat transfer models to predict temperature evolution within structural members, and structural models to evaluate fire-induced structural response. While substantial progress has been achieved in fire and thermal modelling, the structural modelling component, particularly constitutive representation of timber behaviour at elevated temperatures, remains comparatively less developed. This paper presents WoodST, a temperature-dependent plastic–damage constitutive modelling approach developed to advance the structural assessment of timber structures under fire conditions. The key modelling components of WoodST are briefly introduced, and its capabilities are demonstrated through applications to representative timber structural systems, including bending members (LVL, glulam w/o openings, OSB-web I-joists), axially loaded compression members considering stability effects, complex bolted timber connections and assemblies (light wood frame and hybrid timber–concrete floors) involving multiple interacting components and contact behaviour. The presented applications demonstrate the capability of WoodST to capture fire-induced material degradation, nonlinear response, instability, and structural interaction across multiple scales. These advances support performance-based fire design and contribute to the development and implementation of design codes and standards (e.g., CSA O86 and ISO TC92), while facilitating innovation in timber products and structural systems.