An assessment of wind-induced fatigue damage to steel roof claddings on hip-roof buildings

摘要

Wind-induced fatigue loading and damage to screw-fastened light gauge steel roof sheeting on hip-roof buildings are investigated. The magnitude and distribution of wind pressures on three hip roofs of 15~0, 20~0, and 30~0 pitch are first measured at different wind directions in a wind tunnel. Fatigue characteristics of wind pressures, including the number of cycles, cycle histogram, and the maximum peak pressure coefficient range, are then identified using a rainflow count method. Total fatigue loading on the three roofs is then computed using the obtained fatigue characteristis and information on wind climate. Finally, fatigue damage to screw-fastened light gauge steel roof sheeting is assessed in terms of previously-obtained S-N curves and a modified Miner's rule. The resulting distributions of fatigue damage index over the hip roofs clearly exhibit the critical areas which are vulnerable to wind-induced fatigue damage. The roof pitch significantly affects both the critical area and fatigue damage index.