Experimental and numerical studies of thin steel roof battens under wind uplift loads

Thin profiled steel roof sheeting and battens are increasingly used in the construction of roofing systems in buildings in Australia. Past wind damage investigations have shown that roof sheeting failures occurred frequently due to localized failures at their screw connections to battens. However, the batten to rafter or truss connections are now the weakest link in the uplift wind loading chain as shown by recent wind events. Therefore a detailed investigation including both experimental and numerical studies was undertaken to investigate the pull-through failures of roof battens at their connections to rafter/truss. More than 300 small scale tests of battens and two full scale tests of roofing systems were undertaken to investigate the localized pull-through failure while finite element analyses (FEA) of tested battens were also undertaken. Appropriate failure criteria were included in FEA to simulate the local pull-through failures around the screw fasteners in the bottom flanges. This paper presents the details of the experimental and numerical studies and the results. It proposes suitable design rules to determine the pull-through capacities of roof battens under wind uplift loads