A Model for predicting heat transfer through insulated steel-stud wall assemblies exposed to fire


ABSTRACT With the advent of performance-based codes and fire safety design options, the need for validated fire resistance models becomes essential. In this paper, a one-dimensional heat transfer model is presented. The model predicts the temperature distribution across steel stud wall assemblies with either glass or rock fibre insulation in the wall cavity. A number of assumptions were made to reduce the complexity of the model. A comparison between temperature predictions and measured temperatures at different surfaces across loaded and unloaded assemblies is presented. Comparison between the predicted and measured fire resistance for non-loadbearing assemblies is also presented. The model predicts the temperature for the stud flanges on the exposed and unexposed sides that are necessary for predicting the fire resistance of loadbearing wall assemblies. Limitations of the model and future improvements are identified. RES

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    ABSTRACT: Although a few fire experiments have been carried out on load-bearing cold-formed steel (CFS) wall systems, the understanding of their fire performance is still limited, and further parametric analysis based on such experiments is expensive and time-consuming. This paper presents a simplified numerical approach to predicting the thermal and mechanical responses of CFS wall systems in fire. Thermal physical property experiments were carried out to measure the essential material properties. With those material properties as inputs, a one-dimensional thermal response model was developed to predict the heat transfer across the cross section of CFS wall systems. Both heat convection and radiation were considered in the thermal boundary conditions. The governing equation was expressed in the form of implicit finite differential equations and solved using the Gauss-Seidel method. The model predictions of temperature responses of CFS wall systems were in good agreement with the measured temperature responses in the fire experiments and also compared well to the modeling results in literature with improved efficiency and convergence in computation. In addition, a thermomechanical response model was developed to predict the time-dependent lateral deflection and fire resistance time for CFS wall systems in fire and was validated by the experimental results in literature. All these studies provide an efficient approach for the fire performance analysis of load-bearing CFS wall systems.
    Journal of Structural Engineering 01/2013; 140(8). · 1.49 Impact Factor


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