different stiffness & nonlinear element

[Eli]

Hi dear all,

I want to assign different stiffness to columns (k, 2k, 3k, …) in pushover analysis. Is there any ‎nonlinear element which define k (or I)? ‎
Or
I have to change columns stiffness by changing their sections?‎

[fmk]

is this one element with different sections along it's length or multiple analysis?

if one element, you do have the option of specifying different sections in the command line for both disp and fore beam column elements. the documention is there for the disp beam column. i will see if we can get the author to update it for the force beam column (though same command should work for both, just change eleType).

remember that the sections are located at the gauss points. so each section will depend on num integration points, integration type and location (two ele use different default integration rules).

[Eli]

Thanks dear frank

I mean multiple analysis and i want to define initial stiffness of columns by elements properties. for example: first story: 2k and second story: k.
in linear analysis we can use elastic beam column element. what about nonlinear analysis?