Capacity design is a part of seismic check and ensures that the joint has sufficient deformation capacity.
The connections must be able to safely transfer the force necessary to create a plastic hinge in a dissipative item. The dissipative item is selected by user alongside with the connection coefficient ηj taken from GB 50017-2017, Table 17.2.9. The connection coefficient ηj is divided between the overstrength factor γov and strain-hardening factor γsh; ηj = γovγsh. Strain-hardening factor γsh is defined by user and it is recommended as γsh = 1.1 for beam in moment resisting frame and γsh = 1.0 for other dissipative items. It is recommended to choose the safer ηj; e.g. ηj = 1.35 for the dissipative beam from steel grade Q345 in moment resisting frame for the checks of both welds and bolts.
Connection coefficient ηj according to Table 17.2.9
Material diagram of dissipative item