Use of Pushover Analysis to Assess System Ultimate Strength
Notes:
Depending on the performance objectives selected by the owner, nonlinear "pushover" analysis methods may be necessary. However, the target of the wind pushover analysis would primarily be strength rather than displacement, since wind loads would not be generally diminished by the reduced structural frequency resulting from inelastic behavior.
As shown in the figure, if the owner accepted a lower performance objective, certain members with adequate ductility could be allowed to behave in the post-yield range at this ultimate state, as long as the remaining system maintained sufficient stiffness and strength to prevent excessive drift or collapse. An inelastic "pushover" analysis would determine whether the structural system could reach a "target ultimate strength" within limits on member deformation.