Framework for structural damping predictor models based on stick-slip mechanism for use in wind-resistant design of buildings

Current structural damping predictor models for buildings are based on measurements at amplitudes that are very low relative to those corresponding to wind-resistant design. They also assume that damping continuously increases with amplitude, or that it reaches a maximum value that is assumed to extend to wind-resistant design amplitude levels. However, some recent measurements at sufficiently higher amplitudes clearly show that damping could actually decrease with amplitude after reaching a maximum value. An earlier paper demonstrated the stick-slip phenomenon to describe the primary mechanism behind such increase and decrease of damping with amplitude. In the current paper, results from a study of multiple-stick-slip-component systems are further analyzed to arrive at a framework for new predictor models. Four different approaches are proposed, and are first illustrated for damping estimates of hypothetical steel buildings. Possible modifications to an existing predictor model are then demonstrated, and different estimates are discussed for one actual building. Finally, it is shown that, with the use of such a framework, the increase in wind loads would not be so significantly higher, but these are still to be considered together with higher wind load factors or recommended lower damping values that account for damping uncertainty.