How to model viscous dampers between stories

lexie.coffee · Post by **lexie.coffee** » Tue Mar 08, 2005 11:59 pm

Hi everyone,

Ask a stupid question about modeling dampers. I want to put braces between each stories, and put dashpots on them. I used zerolength elements , I am wondering which material comment should I use to model those dashpots? If I use Viscous Material, what's the normal values for C & alpha?

Thanks

lish hit · Post by **lish hit** » Sun Mar 13, 2005 1:45 am

The command:

uniaxialMaterial Viscous $matTag $C $alpha

i.e. stress =C(strain-rate)alpha

a exampl le give you,in e.q M*A+C*V+K*X=-M*Ag (1), V is the derivative of X,so you can compute the iterm C*V with this command,like,where use C=damping and alpha=1.

then puts the material into the zerolength elements.

Here also a useful material can model damper:

uniaxialMaterial Elastic $matTag $E <$eta>
stress = E*strain + eta*strainrate
this materail can model the last two iterm of e.q (1) when the syterm in elastic.