nonlinear

imancivil · Post by **imancivil** » Mon Apr 14, 2008 8:03 am

Hi all,

I want to model 3D truss to achieve a nonlinear analysis (material non-linearity and geometric non-linearity).
Would you please answer my questions? Thanks in advance.

1. Can truss element include post-buckling behavior? if so,how can I do it?
2. Can opensees explicitly model P-Delta effects on 3D truss structure? if so,how can I do it?

silvia · Post by **silvia** » Mon Apr 14, 2008 8:35 am

use the corotational truss.

pejman_opensees · Post by **pejman_opensees** » Mon Apr 14, 2008 8:59 pm

Corotational truss element is great for modeling truss elements having large displacement capability. But sometimes we need to have end-hinged type buckling rather than portal-type buckling. End-hinged typed buckling means basically a simple both-end-hinged beam in which buckling is encounterd in its first natural mode of vibration. For instance you may consider almost all braces buckle in this way. If this is the case, you need to define a middle node with appropriate imperfection to allow the brace to buckle. As a consequence you need to use beam type element to avoid any unstability. I recommende that you use two force beam column elements with proper imperfection in one end and apprppriate equalDOF at the other end to model a truss element.

imancivil · Post by **imancivil** » Mon Apr 14, 2008 10:29 pm

Thanks a lot.

esi_opensees · Post by **esi_opensees** » Mon Apr 14, 2008 10:59 pm

Hello

I have the same question about this. Can corotational truss explicitly include post-buckling behavior?