how to model plastic hinge in 3d frame model

[showmaker]

i modeled 3d frame in openseespy
in experiment,a special connection is setted on the beam,away from beam-column joint about 140mm,this connection has a special moment-rotation relationship,so i want to use zerolength element to simulate this connection,by:

ops.element('zeroLength',ele0tag, inode,jnode, '-mat',3,3,3,3,3,2,'-dir',1,2,3,4,5,6)

material 2 is force-deformation relationship of connection that has been priviously defined,freedom 6 is local Rz,since i don't focus on deformation of other freedom,so material 3 is elastic material with very large stiffness.i run the script,but the result is not desirable.
so i changed another way by

ops.element('zeroLength',ele0tag, inode,jnode, '-mat',2,'-dir',6)
ops.equalDOF(i,i+1,1,2,3,4,5)

the result is unreasonable too
so how can i use plastic hinge in 3d model in right way?