Nonlinear dynamic behavior of steel framed roof structure with self-centering members under extreme transient wind load

摘要

Collapse of roof could cause severe economic loss and poses safety risk to residents in the building. This paper presents a nonlinear dynamic analysis of steel framed roof structures with force limiting devices under combined static and transient wind loading. Two types of force limiting devices - one with self-centering behavior and the other exhibiting bilinear-like hysteresis are examined for roof collapse prevention. A nonlinear dynamic analysis that accounts for both material and geometrical nonlinearities was carried out for this simulation study. Two types of steel framed roof structures - a K-series steel joist and an arch truss are selected as the prototype roof frame in this study. It is found that installing force limiting devices at intentionally weakened zone of the prototype steel framed roof structures helps mitigating the displacement demand of the roof frame structure under transient up-lift wind pressure and thus reduce the dynamic collapse risk. Furthermore, the force limiting devices with self-centering behavior minimizes the residual deflection of the roof structures after the wind event.