Inelastic Behavior and Collapse Risk for Buildings Subjected to Wind Loads

This paper explores the inelastic behavior and the risk of collapse of buildings designed for wind loads. The approach used is similar to the prevailing method utilized for seismic loads (FEMA P-695). Single-degree-of-freedom models are used to represent the hysteretic behavior of the actual main wind-force resisting systems, including in-cycle degradation. An ensemble of wind load records from boundary-layer wind tunnel tests are applied to capture both along-wind and cross-wind effects. Wind loads are then scaled (intensified corresponding to increasing hazard levels) using an incremental dynamic analysis (IDA) approach until lateral instability and collapse occurs. The risk of collapse is quantified by incorporating epistemic uncertainty and integrating collapse fragility with ASCE 7-10 wind speed data.