Behavior factor of dual systems with BRBs and semi-rigid connections

The use of BRBs into a typical European building with braced structure, whereby all the beam-to-column connections are perfectly pinned, may be low effective. In fact, these structures are low-redundant and prone to develop soft story collapse mechanisms. The concentration of drift demand in few stories precludes the full exploitation of the deformation capacity of all the BRBs inserted into the frame, and it partially reduces the benefit they can provide. A more effective structural system may be obtained by coupling frames with BRBs with frames with semi-rigid connections. This paper proposes a design procedure for this dual system and presents the calibration of the behavior factor. To this end, a set of frames is designed considering several values of behavior factor and the response of the obtained frames is determined by nonlinear dynamic analysis. Hence, the behavior factor that allows the frames to meet the performance objective requirement of EuroCode 8 is determined.