Robustness of automated rack-supported warehouses in case of localized fires

Automated rack-supported warehouses (ARSWs) are increasingly used in modern logistics due to their capacity and efficiency. While their structural behavior under static and seismic conditions is well documented, their fire-induced responses remain largely unexplored. Existing studies focus on active fire protection measures, yet these may fail or be insufficient, leaving no robust design strategies to ensure structural integrity in a fire scenario. This research addresses this gap by investigating the progressive collapse behavior of ARSWs under fire conditions through a performance-based approach. A three-step numerical methodology is proposed, combining static, dynamic implicit, and dynamic explicit analyses to overcome the numerical singularities that commonly block conventional analysis methods. This approach enables the accurate simulation of post-critical behavior, capturing phenomena such as large displacements, buckling, and contact interactions. Several case studies are examined, including localized and fully developed fires. The results highlight the critical role of the roof truss in redistributing forces during fire-induced degradation, the stabilizing effect of bracing towers in down-aisle directions, and the importance of robust beam-to-column connections to withstand elevated thermal and mechanical demands. By identifying these key factors and demonstrating that progressive collapse can be mitigated through informed structural design, this study lays the groundwork for developing more effective and economical fire resilience strategies in ARSWs.