Question about Links elements (Sap2000) 1

[Roycronos]

Hello,

I need to model a element to have different stiffness values in compresion and tension, but both together

I am trying to model a link in SAP 2000 (nonlinear analysis), but I need the links to have different stiffness values in compression and tensile, but both together.

I read anothre thread where someone said with a link with Gap and Hook, but to do this, i need to make 2 "links" in the same place? or how can be it done?
Another solution to do it is with "Multilinear Elastic or Plastic link" but i don't understand how to define it really.

Thanks in advance,

Atte.
Rodrigo Mercado.

 

[kostast88]

Define a single multilinear plastic element, and enable the DOFs you are interested in. For the nonlinear DOFs (I suspect rotation or θz) check the nonlinear option, and define a backbone curve with different properties for positive and negative force-deformation(the stifness is derived as the slope of the lines you define).

The effective stifness option in the same tab is enabled for linear analysis only.So you will get the different behaviour in positive and negative moments.However what I described, is an example of a rotational spring,which is the simplest thing to model with a link element.If you want something more complex,you could provide some more detail to the community to answer you more properly.

 

[johnbridge231]

kostast88 is right, a multilinear plastic link would work properly in that case.

[Γεια σου Κώστα παιχταρά!]


Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[Roycronos]

Thanks to both, that's just the case that less I know, but if you tell me that this is the best option, then I will study this case. Thank you very much again.