Structural Behaviour of Automated Rack Supported Warehouses in Fire Situation

This work deals with the fire modelling and structural thermo-mechanical assessment of Automated Rack Supported Warehouses (ARSWs), which are a particular type of steel racks that combines the structural efficiency of steel constructions with automated machines for handling stored products. The study is composed of two phases: the first one regards the investigation of the fire modelling which can be used in a multi-depth ARSW structure, by adopting localized fire models, zone models, and Computational Fluid Dynamics models. A fire model that allows vertical and horizontal propagation, starting from a localized fire, evaluated and validated against experimental results available in the literature, is proposed. Also, a criterion to evaluate the vertical and horizontal propagation times is provided. The second part of the work focuses on the study of the structural collapse mechanism and on the methodologies of analysis that the designer should adopt to properly interpret it. Several thermo-mechanical analyses were carried out by using all the results of the proposed fire model and compared with different fire models available in the literature. To correctly analyse the progressive mechanism of collapse, an iterative procedure is proposed by using several subsequent implicit analyses carried out with SAFIR software and comparing this one with an automatic procedure performed through the software ABAQUS CAE, which allows the implementation of implicit/explicit analyses.