Effect of roof shape on wind vulnerability of roof sheathing panels

Abstract

Roofs of low-rise residential structures often suffer great damage during strong wind events. Sheathing loss that occurs due to excessive wind uplift may lead to internal damage due to water ingress and may in worst cases even initiate a progressive collapse of the structure. Hence, sheathings are an important aspect of any engineering-based wind vulnerability model for residential buildings. Vulnerability model is the part of a catastrophe model that relates the hazard intensity to the expected damage. The focus of this study is the application of a Monte Carlo simulation (MCS) based wind vulnerability model for roof sheathings considering the shape irregularities of the roofs of typical low-rise residential structures. The damage curves are derived based on wind tunnel tests on regular and irregular shaped structures. A comparison is made between the roof sheathing vulnerability curves of l-shaped, T-shaped, C-shaped, and rectangular shaped roofs. Through this comparison the effect of roof shape on performance of roof sheathings is derived. Newly acquired wind-tunnel data for irregular shaped structures are used for the analysis. Peak wind loads on roof sheathing are estimated based on a Hermite polynomial based probability distribution model for the wind pressure coefficients. The probability of failure of individual roof sheathings and the expected damage at incremental wind speeds is estimated. Significant variation in roof sheathing vulnerability is observed between the non-rectangular and rectangular roof shapes. The most critical directions for different roof shapes are identified, and the most vulnerable locations for roof sheathing damage within typical irregular shaped roofs are shown.