Experimental and Numerical Investigations of Crest-Fixed Corrugated Steel Claddings Under Wind Uplift Loading at Elevated Temperatures

The 2019–2020 Black Summer bushfire in Australia is a good example of the frequent and severe bushfires (wildfires) observed around the world in recent years. Fire-enhanced winds and fire–wind interactions during those bushfire events have caused increased wind velocities in the vicinity of a bushfire front. This can lead to a premature failure of the building envelope, making it vulnerable to ember attack and direct flame contact. In Australia, crest-fixed cold-formed steel (CFS) claddings are commonly used for buildings in bushfire-prone areas because of their non-combustibility. Therefore, this study investigated the pull-through failure behaviour of corrugated CFS claddings under wind uplift/suction loading at elevated temperatures, simulating fire-enhanced winds during a bushfire by means of experimental and numerical studies. Experimental results showed a negligible influence of the thermal expansion of the cladding system on the pull-through failure behaviour, while a significant decrease in pull-through capacity was observed with increasing temperatures. Suitable finite element models were developed, validated and used in a detailed numerical parametric study. Based on the findings from these studies, a design equation was proposed for the pull-through capacity of the crest-fixed corrugated claddings at elevated temperatures.