Robustness of Metal Building Roof Corners under Tornado‐Induced Internal Pressure Variations

Abstract

Metal building systems are commonly used for warehouses, schools, and shelters in rural communities, where their low cost, ease of construction and adaptable structural layouts make them a practical choice. However, these systems are vulnerable to tornado‐induced wind loads, particularly at roof corner regions, where intensified uplift pressures due to turbulent airflow frequently result in fastener‐related failures that compromise the roof panel's integrity. This study investigates the role of fasteners in governing the load‐carrying performance under tornado‐induced wind loads. A detailed shell finite element model representing the corner section of a metal building roof was developed in ABAQUS. The model incorporates material and geometric nonlinearity, as well as standing seam roof and upper frame details. Connector elements are modeled with defined pull‐out and shear capacities, enabling the simulation of both local fastener failure and its impact on panel buckling. Structural response to loading representing pressure measurements on a building model of two opening scenarios, background leakage and background leakage plus a dominant opening, in a tornado‐like vortex were analyzed with maximum mean tangential wind speeds ranging from 30 m/s to 70 m/s. The extent of fastener failure under each configuration and wind speed was quantified, and preliminary fragility curves were developed to characterize the robustness of roof corner assemblies subjected to tornado induced loading. The number and percentage of failed fasteners are used to quantify damage states and to provide insight into the progression of roof panel buckling and failure.