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can any one help me???
this is urgent

yes, the viscoelastic element has either of stiffness and damping components
this twi components have been paralleled together
and modeled as it has Previously mentioned

I did this and the stiffness matrix for structure without damper is correct
but when i add elements of viscoelastic damper, result is not correct
It is the problem

No,I'm looking for stiffness matrix of 2D steel frame structure, in other word "K" in structure motion equation.

I need your help seriously

I used printA command to calculate stiffness matrix of structure for structure without Viscoelastic damper, results were correct but when I added elements of Viscoelastic dampers, the stiffness matrix was not correct Where do you think the problem is? commands for modeling dampers and analyze are as...

is the following viscoelastice damper model correct?
is making the materials parallel correct?

uniaxialMaterial Elastic 1 16.77e6
uniaxialMaterial Viscous 2 2498e3 0.5
uniaxialMaterial Parallel 3 1 2

element twoNodeLink 67 8 16 -mat 3 -dir 1

thanks

Are the commands coming below, correct? do I have to write commands related to gravity loads and gravity commands before these? integrator DisplacementControl 42 1 0.002 system FullGeneral analysis Static analyze 1500 printA -file Stiff.out wipeAnalysis system FullGeneral integrator NewmarkExplicit ...

in structure with viscoelastic damper, can I calculate the stiffness matrix with "printA" command? the calculated answer with this method is correct? integrator LoadControl 1 system FullGeneral analysis Static analyze 1 printA -file Stiff.out wipeAnalysis rayleigh 0.0 0.0 0.0 0.0 system FullGeneral ...

yes, i can.
But the stiffness matrix of structure with damper, that obtained from printA command,is correct?


Your tips are very helpful

when i added elements of dampers to model,the mass matrix was changed
What do you think about the reason of it?
viscoelastic damper is used


thanks for your help

What force should be calculated to obtain hysteresis loop of damper ?
If possible, mention the command


thanks for your help

How can I set the the damping to zero?
have it special command?

thanks

1-is it correct to use command: "printA" for calculating mass matrix as below? do you have any example? integrator LoadControl 1 system FullGeneral analysis Static analyze 1 printA -file Stiff.out wipeAnalysis system FullGeneral integrator NewmarkExplicit 0.5 analysis Transient analyze 1 1. printA -...

thanks for your help

{x ̇(t)} is the vector of global velocity, can I calculate it by " Node recorder command" for one node?