plastic hinge's properties was described in FEMA , i prepared a power point which it can help you and also you can find an example of Stell Brace Hinge in my paper which is attached.
i dont have any experience in concrete brace.
Good luck
Conference Paper Seismic Performance of Stell Tall Buildings with Outrigger S...
do you want to know plastic hinge's properties when brace connects to combined steel section column? as i know the detail of column hasn't any effect on the plastic hinge's properties.but if you are looking for plastic hinge's properties for combined steel section column it changes....