A QUESTION ABOUT UNCRACKED EIGANVALUE(MODAL) ANALYSIS

[snensr]

I modeled a building using infrmFBPH (inelastic force-based plastic hinge ) elements and I realized that changing the plastic hinge length of the structural members( columns, walls and beams in this case) significantly affect the uncracked modal analysis's results. How plastic hinge length make this impact in an elastic linear analysis, this seems weird to me. Can anybody theoretically explain the reason for this behavior?

[seismosoft]

Indeed changing the plastic hinge length in the infrmFBPH element changes considerably the stiffness (and the strength in inelastic analysis) of the member, due to kinematic reasons. It is advisable to keep the default value of the program, unless you have a good reason to change it.

Seismosoft Support