A study on strengthening thin roof battens subjected to pull through failure

cold formed steel is frequently used in contemporary construction, especially as a secondary roof purlin. These sections are typically connected to trapezoidal roofing sheets using screws that self-drill or self-tap, forming an integral part of lightweight roofing systems. Hat-shaped CFS sections are commonly employed as batten members in industrial, commercial and residential buildings due to their structural efficiency and ease of installation. However, recent extreme wind events have revealed a recurring issue: localized pull-through failures occurring at bottom flanges of batten sections where they connect to rafters or trusses. To investigate this failure mechanism, a comprehensive numerical study was conducted using finite element modeling. The analysis incorporated an appropriate failure criterion to accurately forecast when pull-through will begin failure in roof battens. The failure load values, obtained from previous experimental studies, were used as input for the simulation. Key parameters such as total deformation, equivalent (von Mises) stresses, and the highest primary stresses were assessed and compared across various models. These models were initially developed in SolidWorks and later imported into ANSYS for detailed analysis. All material properties, boundary conditions, and loading configurations were appropriately defined. The study first analyzed several existing strengthening techniques before evaluating the performance of newly proposed methods. The results revealed that a combination of two existing strengthening approaches significantly improved the pull-through resistance of the battens, offering the most effective solution among the tested models.