Numerical modelling and design of cold-formed steel batten screw connections subject to pull-out failures at sub-zero temperatures

The roof and wall cladding systems made of thin, high-strength cold-formed steel (CFS) battens and claddings are vulnerable to damage during snow and windstorm events, known as blizzards. CFS batten pull-out failures can occur at both connections between cladding and battens and battens and trusses/rafters, however, they are more critical for cladding to batten connections. These localised failures occur when the screw pulls out of the top flange of battens, leading to the complete loss of cladding. This paper uses a detailed numerical study of a range of batten configurations subject to pull-out failures under combined wind action and sub-zero temperatures. The study includes the development of finite element models simulating the pull-out failures, their validation, parametric study and its findings. Suitable design equations are developed for predicting the pull-out capacities of CFS batten screw connections at sub-zero temperatures.