Reduction of Stiffness in NonLinear Analysis

[KiriakosCE]

A theoretical question:
I am running a Non Linear static analysis of a concrete frame-wall building (dual system), that i designed and i want to see its response.

In order to get the correct response of the model, do i have to reduce the stiffness of the possible hinges locations? (beams and columns bases, because of the capacity design)

Or is it taken into account automatically by the creation of the hinges?

 

[drile007]

I think that you should not reduce the stiffness, because the cracking is captured by defining hinge properties, but I'm not 95%.

 

[KiriakosCE]

Thanks for the reply!
At first i had the same opinion with you! And it makes sense, because when you define hinge properties to an element, then its response will be inelastic. (Let's say flexural response) When the moments of an element surpass the yeild moment (until now we had elastic response with the full section of our element), then because of the inelastic response,(maybe we will have strain-hardening, maybe not), the capability of our element to carry out moments will drop down significantly. So i thought that in the above procedure, cracking was taken into consideration, and i didn't have to reduce the stiffness of the element... but i am not sure!