Comparison of two type of modeling

[kavir]

Hi
I Model same MRF(4 bay & 3 story) with two manner. first Model it by distributed plasticity element without panelzone and its material is bi-linear,
second i model same frame by elastic element with concentrated plastic hing and its material is MIK (Modified Ibarra Krawinkler).
but in first model the period of structure is 1.67s and in second model period is 1.7s.

my question is :
Should the period in the model is the same ? or this difference is only natural.

[fmk]

difference is a consequence of your modeling choices (particularly the concentrated model) .. the distributed choice modifies the values less than the concentrated choice (compare with an elastic model to see for yourself) .. is 1.67 versus 1.7 important, vary say E in the elastic model to see how much you would change this bye to get the same reduction .. the end results if building goes nonlinear are going to change more due to modeling choices than the result of differing eigenvalues.

[EQpkm]

Hi,

may i have your models details? i have got confused with my comparisons in this two method of modeling!!

thanks

[zlatkov]

Hi,

in my experience getting such close result for different models in initial modulus terms is quite impressive (I assume initial material moduli are different). Compare pushover curves instead as indirectly suggested by fmk.

regards