Eigen value analysis

[Prayag Sayani]

I am trying to find fundamental time period of a 3 story 4 bay frame model.
I am using following cases for modelling of beams and columns,
1. Elasticbeamcolumn elements for beams and columns
2. Nonlinearbeamcolumn element for columns and beams with steel01 material
3. nonlinearbeamcolumn elelment for columns and beamwithhinges element for beams with hardening material.

why I am getting diffrent time period in each case?

Thanks in advance,

[silvia]

because they are all different models.