ForceFrame

Fig. 1: Representation of the OpenSees forceBeamColumn element rendered with veux.

Two-node force formulation for 3D frames. [1] [2].

Python (RT)

Model.element("ForceFrame", tag, nodes, section=None, transform=None, integration=None, *args)

Parameters:

• tag (integer) – unique Element tag

• nodes (tuple) – tuple of two Node tags

• section (integer) – integer tag identifying a Section.

• transform (integer) – identifier for previously-defined frame transformation

• integration – identifier for previously-defined integration rule.

This formulation supports higher order strain measures and shear deformations.

The valid eleResponse queries to this element are:

• "force".

• "section": Make a query to a specific section along the element:

  model.eleResponse(element, "section", section, *section-args)
  

Examples

Using the ShearFiber section, querries can be made to the material at a specific fiber location within the section as follows:

model.eleResponse(element, "section", section, "fiber", fiber, "stress")

where section is the section number along the element (1 to number of sections defined by the integration rule).

References

[1]

Spacone, E., V. Ciampi, and F. C. Filippou (1996). “Mixed Formulation of Nonlinear Beam Finite Element.” Computers and Structures, 58(1):71-83.

[2]

Lee, C.‐L., and F. C. Filippou. “Frame Elements with Mixed Formulation for Singular Section Response.” International Journal for Numerical Methods in Engineering 78, no. 11 (June 11, 2009): 1320–44. https://doi.org/10.1002/nme.2531.

Code developed by: Claudio M. Perez, fcf, Michael H. Scott, fmk