ANSYS Tutorial : Nonlinear analysis of Deep Reinforced Concrete Beam and compare with test results
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- Опубликовано: 20 авг 2024
- Link for load test data, import geometry, APDL command, and graph:
drive.google.c...
My ANSYS Tutorial Playlist :
• ANSYS tutorial for pra...
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The workflow demonstrated in this tutorial is intended for practical purposes rather than research purposes.
This tutorial will show how to make a fast model for nonlinear analysis of reinforced concrete elements while sacrificing some accuracy in comparison with the workflow that specifically intended for research which takes much more time.
First of all,
Thank you for your kindness and that great effort
Secondly,
I’m using WorkBench 2020. And here is problems that I faced and solved:
1) I have chosen different names for “Named Selection” after that Elements haven’t been assigned correctly so, if anyone faces that problem the named selections have to be exactly like tutorial or you have to edit APDL command.
2) If you are using Workbench older than 2019 R2, you may not find “link/truss” at model type drop list so please update your version. Or if you are an expert you can apply boundary displacement to assign link properties and that’s hard way to be followed.
3) If you are using WB 2020 and you got error that solution didn’t converge, you have to review meshes that have been created via software. I think you will find that rebars haven’t been meshes correctly and the solution is to choose the rebars and add “sizing” method for mesh size 15 mm with changing “behavior” to “Hard” not “Soft”
My question is although I have revised meshes for rebars solution didn’t converge at 4% would you mind giving me your mail so we can contact or having a meeting via team viewer?
@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.
For anyone who try to re-model several times but the solution could not be finished or converged. Try to check the unit. In the Mechanical module, from the Home tab, select "Unit" and then choose Metric (mm, kg, N, s).
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?"
Love you
Thank you for the video!
Did you take into account the self-weight of reinforced concrete in this calculation?
Thank you very much....I just love your videos...Keep making new video on ANSYS FEM analysis.... Can you please make videos on steel connection like end plate moment connection/?? thank you
thank you very much for the tutorial, my question is that the drawing of the concrete structure only should be attached with the drawing of the reinforcement (as layers), is there a tutorial to clarify this.
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.
Hello, I proceeded in the order of the videos, but in my case, the Force Convergence graph came out differently, and the result came out differently accordingly. Can you please advise what is wrong? Is there anything I can check..I am using 2019 R1. thank you.
error message : One or more contact pairs exceeds contact small sliding assumption, check your results carefully. Consider using Large Deflection or turning off Small Sliding on the offending contact pair(s). You may select the first offending pair via RMB on this warning in the Messages window. Additionally, you can use the “Number With Too Much Sliding” Contact Results Tracker to locate any additional pairs.
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.
How do I create the APDL commands to use the SOLID65? I am having trouble doing that. I am currently modelling a beam column joint with SOLID65 element for concrete.
Thank You So much Sir,Can you please do a video for Simulation Modelling of Corrosion in Concrete beam for Propagation of Corrosion
I created geometry in design modeler.
Dear, Eng
Why the load-deflection extracted from Ansys workbench did not descend after peaking value as in experimental curve?
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?
Thank you so much for your great explanation. I will be waiting for a masonry solution with SOLID65.
please make videos on rcc beam with opening
Thank you and congratulations for the video. However, I am surprised that I have followed each of your steps but I could not get the results. Is it possible due to change in the version?
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.
Hi, Thanks for the video. Why is the model type taken as Link/Truss when there is the option reinforcement available?
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
Hi, what are the R and RMORE commands from here? How does it affect for solution
Hey guru. I use arc's as a rebar (half of cylindrical wall), but my arc's not dividing at elements as your. Each arc is SINGLE linc element, and it is just straight segment, of begin to end point of arc . Help me please. How to make arc of some elements? Phisycally divide arc in AutoCAD?
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.
Excuse me sir, if I want to analyze this deep beam without reinforcement. How to do? Can I just suppress geometry of the LONGRebar and STR and solve it again? Thank you.
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.
Hi can u do an analysis on concrete brick under ststic load?
Why it not have sound
Sir
Would be you please help with the procedure to be followed to use RESTART analysis to increment the Load in every Load Step in ANSYS Mechanical APDL. How to create a Restart file
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
I have my own reinforced concrete beam. I want non-linear analyisis of concrete beam. I don't know about commands. How I will create the commands for my concrete. I have stress-strain data.
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.
Great Work, Can i use the process for a column analysis?
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
HI, modeled this many times but still not same results CAN you kindly share the complete ANSYS File.
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 ?
does anybody know why i get the "no b-rep data in input file " error?
That doesn't sound familiar to me, would you care to elaborate more about such an error?
whaT Is the load given here
Hi,i need help in rc beam design for my project... I ll pay the amount for the work. Can you help!
How to model RCC building in ansys
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?
ruclips.net/video/Sg7jmuD7GiY/видео.html