Learning Forum

[Jairo Masapanta]

Hello Ansys Forum. I would like to do the modeling and calibration of the following connection:

I reviewed the available forums and videos and understand the complexity of a reinforced concrete simulation. In this context, I reviewed configurations of solid elements for concrete such as: solid65, CPT195, and solid 185 and line type elements for reinforcement bars using beam, link and reinforcement type elements.
I have followed recommendations by @Wenlong in the forum ttps://forum.ansys.com/forums/topic/error-contact/ for the use of the EREINF command, geometry slices with merge topology and other recommendations given in  “Modeling Rebar Reinforced Concrete on Workbench.pdf"

Other recommendations from the forum /forum/forums/topic/error-with-reinf264-elements/ by @gigihmprayogo to use CPT125 elements for concrete and model the reinforcement bars using solid type elements.

Some other recommendations from @peteroznewman to generate the correct meshing of solid type elements along with line type elements from the forum /forum/forums/topic/solution-not-converged-metric-rc-beam/.

And other forums with information relevant to the application of loads, meshing and concrete modeling have helped me learn something about Ansys.

One of the problems that worries me is the joint behavior of concrete and reinforcement bars when applying cyclic loads, and adding that the concrete will be crossed by a steel beam, its complexity will increase. It is an interesting challenge that I would like to be able to carry out.

I have reviewed some concrete behavior models such as the “microplane material to model concrete damage” Druker-Prager, Menetery-William, and bilinear concrete models recommended in the “Concrete Material Model” forum.

These are my questions:
I would like to consider Mander's model in modeling concrete reinforcements. Mander's model for concrete behavior idealizes the behavior of concrete confined by reinforcing steel. I would like to be able to apply this concrete model through bilinear behavior.

In this sense, is it possible to change the material within a model to consider the modeling results in the elastic stage and then change the material for the inelastic stage? I mean, apply conditions to adjust the behavior of materials through commands.

Due to the convergence problems that can occur when having multiple materials, I would like to ask you about recommendations on the use of combined materials for modeling concrete and reinforcing steel.

Lastly I would like to receive any recommendations: in considering the implementation of non-linear spring like Combin39 for the contact between the reinforcement bars and the concrete to aid convergence, slip interaction between reinforcement bars & concrete (NOT full tied ), and adjust shear reduction coefficient. in Solid 65 model command, mentioned by @abdalla and Dr. / Abdalla Mohamed respectively on /forum/forums/topic/cyclic-loading-from-ansys-workbench/

Any recommendation to open another new Discussion will help me as well.

[John Doyle]

It appears you have done a lot of research already.

As you know, Ansys does not have the "Mander's" Material model.  The closest option might be the Capped Extended Drucker Prager.  Please refer to the Section 4.4.5.1 of the MAPDL Material Reference Guide for more details.

Also, you might want to consider mesh independent reinforcement.  See Section 14.1.3.1 of Structural Analysis Guide for more details.

[Jairo Masapanta]

 

Hello Jhon, thank you for your appreciation, if it helps somebody else I would like to share some observations that I could collect, the combinations of elements and materials that I considered:

Solid185+beam 188 type elements, They have stable behavior

Solid185+ereinf264, there is a compatibility between both elements

Solid185+reinforcement, there is compatibility between both elements

When using elements 264, stresses can only be checked using APDL commands in the Solution menu

 

 

CPT215+solid185 as reinforcement bars. According to comments reviewed in other forums, the solid element CPT215 is not suitable for modeling concrete. Due to the shape of the stirrups shape inside the column, it is not possible to have a geometry with hollow solids. When modeling hollow solids too many errors are generated in the geometry of the solid. When modeling both as solids, the concrete and the reinforcement bar as overlapping, errors getting the mesh will be generated, it happens with any of the topology options.

CPT215+beam elements  or reinforcement: Ansys does not recognize the interation between these elements.

The use of  concrete materials included in Ansys library offers betters and stable outcomes.

 

I have reviewed some information about Transient analysis and explicit dynamic analysis but did not go into depth. That I have read that some authors have managed to obtain complete hysteresis loop from their concrete model, if you have any suggestions about these topics it would also be helpful.

 

And regarding the use of APDL or Python commands to exchange the material according to the stages of the analysis, elastic stage and plastic stage, I also reiterate my question, if you know anything or some examples it will help me.

 

Thanks in advance