@Eslam Ahmed, thank you very much for your tips and sharing. Regarding this deep beam in Workbench 2020R2, I just apply the solution you suggest (hard behavior) and the results look good. I capture the parameters and the results picture as per the following link. drive.google.com/drive/u/0/folders/1CDcHLAnqtHgg1Ti2CQvYLXRALsMXnSy9 Please let me know if this working on your side or not.

@@ThanaponBuamongkolChannel I have got this error message *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 8070. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 8072. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 8104. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 30665. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 8065. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 8096. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 30661. *** ERROR *** CP = 2.125 TIME= 13:35:25 Constraint equation 1 has unused node 30673.

@@ThanaponBuamongkolChannel please send me your email so I can text you directly

@@ThanaponBuamongkolChannel and here you are a warning message Line bodies with type set to Link/Truss or Cable may not be able to solve if Large Deflection is turned off in the Analysis Settings for the model.

The warning that said, "Line bodies with type set to Link/Truss or Cable may not be able to solve if Large Deflection is turned off in the Analysis Settings for the model." ==> This is fine, we don't need large deflection to activate the real cable behavior as all nodes will be constrained to concrete. Therefore, this warning can be completely ignored. According to your error message, "Constraint equation 1 has unused node.... ". Please try to clean/recreate the name selection. And also suppress the SOLID65 assignment and perform the regular linear static analysis to see if the CEINTF is properly working.

In practice, it is better to prepare the rebar model in REVIT. There is a tutorial showing how to prepare a finite element model using REVIT, the video is in my practical REVIT playlist.

@@ThanaponBuamongkolChannel thank you very much sir.

The reinforcement option is the new feature in ANSYS workbench that is intended to be used with the modern ANSYS concrete model. No such feature back when this video was published and also incompatible with SOLID65.

@@ThanaponBuamongkolChannel Thank you. I also dont understand the excel data shown at the beginning (1:34 min). Is it from experimental data?

@@parvathysbiju8367 See 1:24

If you use Workbench 2019, then I think you should try to start modeling all over again by following the steps shown in the video, and you suppose to get the proper results eventually. Please also note that SOLID65 is meshing dependent, therefore, for your first run, try to strictly follow the steps. After you get your first proper results you may play with other parameters as you wish.

Hello I followed the video but I can't divide the element by the rebars

Are you referring to the matching of nodes between the meshing of concrete and the meshing of rebar? If so, you don't have to. The rebars could be embedded within concrete and the nodes could be located anywhere as long as the rebar is inside concrete.

@@ThanaponBuamongkolChannel "I'm sorry to bother you, could you please let me know why you chose 4.0387e-003 instead of 3.6687e-003 in this table? I don't quite understand this part. Why didn't I choose 3.6687e-003?"

Link image: drive.google.com/drive/folders/1VJKWvV9paRQs7BKsP38OXcLPEKplqW7Z?usp=sharing

@@ThanaponBuamongkolChannel "Could I ask one more question: If the concrete beam according to sample 01 doesn't have reinforcement, do I choose e=0.0015, right?"

The workflow could be applied to any kind of reinforced concrete element including reinforced concrete columns. The only exception is that this workflow is not suitable for a problem involving very large deformation due to the limitation of the constraint equation. For example, predicting the nonlinear buckling strength for a very slender column. The deflection of a very slender column (in this case, it is lateral deflection) can be very high at its maximum strength. The load-deflection curve from this workflow can still be accurate at the beginning of loading where deflection is small but can significantly deviate from laboratory results when (lateral) deflection becomes high. In real life reinforced concrete problems, the inaccuracy (of this workflow) in the high deflection zone can be considered irrelevant. Because the serviceability limit state will govern the design long before the lateral deflection of slender column will become large. Therefore, this workflow is still applicable to the slender column in real-life structural problems providing that structural designer follows both the ultimate and serviceability limit state according to the code of practice. However, if the objective is to accurately predict the load-deflection curve of a very slender column in the laboratory, then the constraint equation is not suitable in this case. Instead, use conventional node merging to tie concrete and rebars together which takes a longer time to prepare the finite element model.

​@@ThanaponBuamongkolChannel Im working with a 20cm square column and 75cm length, I applied this workflow and the load-deformation curve is very stiff And please, explain me why in your example the tb_rebarratio is zero in the three directions.

The smeared rebar ratio can be zero in all directions because in this video all the rebars are explicitly modeled using Link elements and there is no numerical difficulty while solving. In another video, there will be a situation that not all rebars are explicitly modeled, therefore, smeared rebars are used in combination with Link elements. Please refer to the following link for the example of using smeared rebar. drive.google.com/drive/u/0/folders/1M4pMD7CPR8QAmBZL2rPztncWiQUuJ4y1

Please scroll down the comments, the only known issue from using ANSYS Workbench 2020 or higher is already been solved.

Thank you I will check.

One of the reason is that the actual stress-strain curve of concrete will descent after its peak while the stress-strain curve of concrete in ANSYS model of this tutorial is never descent as shown here [1:33] and the crushing mode has been discarded as shown here [2:02] with the input value for uniaxial crushing stress equal to a negative one. Predicting the strength degradation is not the purpose of this workflow. The negative slope of structural stiffness (strength degradation) will usually require several restart analysis which in turn time-consuming while contributes very little to no contribution at all in most of the real structural design. For the specific structural design problem such as a performance-based design that would require strength degradation to construct the proper hysteresis backbone curve for further used in the nonlinear time-history analysis, then workflow in this tutorial is not suitable and require another approach to capture structural behavior properly.

@@ThanaponBuamongkolChannel Ok, well, But I am asking you, can workbench simulate the strength degradation and descending part of concrete beams accurately and define the failure point of the beam, if yes, please tell me HOW? Another question, please tell me, what is the approximately time consuming to model large concrete model as deep RC beam with 8 m span and 1m x 3 m cross section with mesh size = 50 mm?

That doesn't sound familiar to me, would you care to elaborate more about such an error?

I put some document I have in the shared link below: drive.google.com/drive/u/0/folders/1o2lD4JDDsaaZyF_ndOLqIieM5HwpOwKv For more information, you can try to google search something like "ANSYS restart analysis". With the restarts feature, you will be able to adjust the substep size every time your solution fails to converge. Every time you restart, the analysis will continue right after where the solution just fails.

@@ThanaponBuamongkolChannel This Procedure is for Workbench Sir but I am using Mechanical APDL to model..How do I restart Analysis in APDL

ANSYS is not a user friendly for NL-RC structure. In order to obtain a reliable result, a certain level of understanding regarding the APDL command is required. My playlist already includes various structural elements, the core APDL command is pretty much a similar pattern.

Yes, that is correct. But please remind that without reinforcement, the structural behavior will be very brittle and the solution will not be converged right after cracking occur (not without multiple restart analysis). The Microplane model should be more suitable for plain concrete than SOLID65.

Thank you very much, sir.

Please scroll down for the comments, most issue regarding this example has already been discussed. You will be able to achieve the correct results eventually, don't give up.

@ThanaponBuamongkolChannel I am using ansys 2020 and i am failing to get rebar modeled as link is being contacted with concrete. There is no contact between concrete and rebar

@@zaes121 The solution for your issue is already provided in the comments. Please look at the comments by @eslamahmed

@ThanaponBuamongkolChannel Is it possible to pay you for a 30 minite online session with you ? And get a personal help ?

If the arc does not properly show in the SpaceClaim then you should split then into multi-straight lines. But normally, Space Claim could handle the curve line just fine. Then, if the meshing of a single straight line still persists instead of multi-straight lines meshing, try meshing with hard behavior mesh setting. The setting explanation could be found in some of the pinned comments with my videos but I don't recall which one.

@@ThanaponBuamongkolChannel Thank you very much. Tomorrow I will try to do it. Bot today another paradox happened, I downloaded all the materials for this example and did everything as you step by step. As a result, the STR rebar are divided into elements and the horizontal rebar isnt divided (one FE on line). I confused :(. Maybe a problem in my workbench 2020...

It is the hard behavior meshing. Check out the pinned comment I mentioned earlier. Then you will be good to go.

Actually, @eslamahmed7022 already explained this here. Check out his comments.

@@ThanaponBuamongkolChannel Thanks a lot. Excuse my inattention.

Although it is possible to model the whole building in ANSYS, that is not what ANSYS is good at. There is other FE software such as ETABS, MIDAS, PROTA,... that handles line elements for building analysis much better than ANSYS. ANSYS is suitable for the local structural element such as structural steel connection, transfer beam, deep beam, thick foundation, post-tensioned anchorage,..etc.

@@ThanaponBuamongkolChannel Any plans to create a video on transfer beam?

@@pulkitvelani Check out the playlist. The heavily reinforced concrete is a transfer beam in a tall building.

@@ThanaponBuamongkolChannel : Sorry, I could not locate any video with confidence. Are you referring to this video? kzfaq.info/get/bejne/ic1nndCmqZ2rmY0.html