modelling brace with friction damper

asra · Post by **asra** » Thu Sep 18, 2008 11:28 am

dear silvia
thanks alot for your useful answers.when i want to model friction damper in brace in momoent resistant frame,i use from truss element for brace and zero length element for friction damper .system fail because three node align in straight so i should equal DOF to resistent frame to act but the problem is that moment act to brace .....what can i do...i constrained which node and how i can constrained node(only with equal DOF?)if you want i send you the program thanks alot

silvia · Post by **silvia** » Thu Sep 18, 2008 1:48 pm

yes, equal dof would be the best way to do it.

asra · Post by **asra** » Thu Sep 18, 2008 10:43 pm

i constraine which node to truss act as brace and either system dosent fail?

silvia · Post by **silvia** » Fri Sep 19, 2008 5:24 am

please this/work through this one.
rotations at the truss ends need to be constrained.

asra · Post by **asra** » Sat Sep 20, 2008 7:44 am

if i constraine the nodes of truss then ,moment and shear force impose to
truss.but in friction moment resistant frame nodes of brace is pin.so i should restraine which node?

silvia · Post by **silvia** » Sat Sep 20, 2008 8:25 am

the truss will not take those moments.
if you have all trusses, change to ndf=2

dunzo123 · Post by **dunzo123** » Fri Oct 03, 2008 10:06 am

silvia wrote:the truss will not take those moments.
if you have all trusses, change to ndf=2

Can you send me your program