Best element for handling axial load and biaxial bending?

[epsilon]

Hi,
I need to analyze a structure consist of armed concrete beam and columns (say for example single span single level frame at simplest form)
Need static nonlinear (both material and geometrical non-linearity) analysis .
I'm aware of fiber element, which could be used to model material non-linearity. is there any other 1D element which can be used to model material non-linearity of concrete beam or column? note that to reduce computation cost, I rather to reduce DoFs by use of 1d elements (like beam column) instead of 2d (like shell) or 3d (like brick).

Thanks

[mhscott]

You don't have to use fiber sections. You can, for example, use a section aggregator inside a force-based element.
https://portwooddigital.com/2021/07/04/ ... ggregated/

[epsilon]

You don't have to use fiber sections. You can, for example, use a section aggregator inside a force-based element.
https://portwooddigital.com/2021/07/04/ ... ggregated/

Hello,
Thank you for the link.
I just interest in static analysis, so I think i do not need hysteresis as in the link. What i do need right no is taking the interaction of axial load and biaxial bending into account for analysis. the Euler hypothesis about beams which plane sections remain plane. and also uniaxial material.
For example this simple case:


L = 3m and P = 10kN

and this section



with steel and concrete with the uniaxial non-linear material:





So what other element expect fiber element i can use for this purpose?

There is loading, but there is NO unloading, so material stress-strain curve is NOT depended to loading

Thanks in advanced

[mhscott]

The section aggregator is not limited to cyclic loading (nothing in OpenSees is). You can use the aggregator shown in the link for monotonic loading too.