Steel bar sliding in concrete block

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Күн бұрын

Пікірлер: 40

@aliasd3328 3 жыл бұрын

Thank you dr ... plz you promised us to make video about CFRP bar as a NSM techinque ... again thanks to this great work

@vandangtran6454 3 жыл бұрын

yes, i want to do but not much time this moment. I'll try

@minhajulbariprince8977 11 ай бұрын

3:17 Hello, Dr. Can I know why you use the concrete surface hole as the master and the rebar surface as the slave? Isn't the rebar surface more rigid than the concrete surface? In that case, isn't the rebar surface supposed to be the master? I might be wrong; can you please clear up my confusion?

@vandangtran6454 11 ай бұрын

Hello, you're right. In some cases, you need to define a particular surface, like a slave surface or a master surface. Particularly, the calculations present a problem of divergence. But I don't think there's any difference in the results for my model, because the master and slave surfaces are the same type and the same size, and they only slide, not penetrate. You can test and tell me the results if you like. Thank you for your comment! BR.

@costigohgpmvula9626 Жыл бұрын

Hello Dr., is it possible to have a complete tutorial? I would like to model a pullout test to evaluate the bond strength using two different concrete strengths. How did you centrally embed the rebar?

@vandangtran6454 Жыл бұрын

Hello, the abaqus model has been shared on my chanel (community). Best regards

@nafissasakhri7568 Жыл бұрын

Hello Sir, please how to do the partition of an embedded steel rebar according to its host dowel concrete?

@fayevong99 Жыл бұрын

Hi, dr, do you mind do a pull out test in concrete for reinforcement bar, currently studying and stuck in the model 😢

@vandangtran6454 Жыл бұрын

Hello Faye, tell me where you are stuck? can you explain to me in detail by mail?

@fayevong99 Жыл бұрын

Hi Dr, actually I am doing the modelling of pull out test for reinforcement concrete with confinement, based on the experiment,the concrete will crack and fail first within a max load , the reinforce my bar will slip, but in my modelling, I think because I am using tie constraints in ABAQUS and what I made become the reinforcement bar will fail first and cannot get the maximum load that concrete fail, may I ask how to tie the concrete with the bar and how can I finding the maximum load that concrete will fail in modelling in Abaqus ? Is that possible to made that😭 sorry and thank you so much

@vandangtran6454 Жыл бұрын

@@fayevong99 Hi Faye, first of all, we need to talk about the phenomenon of failure of the test that you explained. we can see that the concrete has been damaged by the cracks. there are therefore two types of cracks (local and global), here we're talking about global cracks. The cracks appear because the reinforcement (steel bar) has exceeded its capacity and is no longer able to hold the concrete. Once the concrete is damaged, the steel bar can slip. However, before the concrete is damaged, the reinforcement is considered not to have slipped into the concrete. Ok! Now it all depends on your objective. If you want to simulate the overall behavior of the specimen with a combination of steel and concrete behavior, I think that's sufficient for what you're doing (so the rebar is embedded in the concrete). By the way, if you really want to simulate rebar slippage, i.e. the phase after concrete damage, you'd have to create the 3D model as shown in this video. if you have other questions, don't hesitate!

@fayevong99 Жыл бұрын

⁠@@vandangtran6454 Hi Dr, may I ask if I simulate rebar slippage, am I be able to find the maximum force that cause concrete to fail and crack? Btw Thank you so much for ur clear explanation and passionate✨

@fayevong99 Жыл бұрын

@@vandangtran6454 Hi Dr, actually the objective of my project is to determine the bone strength between reinforcement bar and concrete, but in order to find the bone strength, I need to obtain the maximum forces/ load that causes concrete to fail

@sinakazemi3554 2 жыл бұрын

Hello Sir. Thank you for the modeling. I need to know how I can get the load-displacement curve? (actually, I need to know how to extract the load data on the tip of the rebar)

@vandangtran6454 2 жыл бұрын

Hello! first of all, you have to choose the point where you want to exploit the displacement and the area where you want to exploit the load. To do this, you will find how to do it at 11:20 in the video below: kzbin.info/www/bejne/n4SYdYWgm9yco8U Then, to exploit the load-displacement curve, you can follow the same video at 16:54 Regards!

@YapingWang-x8g 2 жыл бұрын

Hi, thanks for sharing. Just wondering why you create interactions for the same surface pair?

@YapingWang-x8g 2 жыл бұрын

I have tried a similar model, but the Mises always turns to be near zone. I also used Cohesive contact. Would you please give some advice?

@vandangtran6454 2 жыл бұрын

@@YapingWang-x8g Hi, I have created two interactions, one for a pair of surfaces consisting of a concrete surface and another of steel bar, other for the other contacts except for the pair of selected surfaces. It would be necessary to choose well the surfaces in contact

@YapingWang-x8g 2 жыл бұрын

@@vandangtran6454 Thanks for your reply. Would you mind sharing the dimension of the rebar and the hole in the concrete? I used the same dimension for both and the Mises results turns out to be zero. I was wondering if the dimension is the problem.

@engrsherkhan8230 Жыл бұрын

Dear Van Dang Tran, I hope you are fine. I have watched hundreds of tutorials to solve my problem. unfortunately, I did not reach a solution. after watching your tutorials, I got near to the solution. I want to model the pull-out test such that I want the cohesive behavior to be inserted between the concrete and rebar which you have done in this tutorial. however, only the thing I am stuck on now is creating the surfaces of embedded rebar and of the region of concrete where the rebar interacts with it. you are doing the same work I want to do. would you please do the work you did in this video from start to end in detail such that the bond between the rebar and concrete is represented by cohesive behavior as is done in this tutorial? But only the problem is to create the surfaces so that they are assigned cohesive behavior. Notice that I am not talking about creating cohesive elements (inserting zero-thickness elements and then assigning them a cohesive behavior). However, it would be a blessing if you make videos for both methods.

@maingocphuonguyen7050 Жыл бұрын

Chào thầy ạ, thầy cho con hỏi là làm sao xác định được các giá trị của Knn, Kss, Ktt của cohesive behavior, và các giá trị của damage (normal, shear,....). Con cảm ơn thầy

@vandangtran6454 Жыл бұрын

Chào em, các giá trị này là các giá trị giả định của mô hình traction-separation model; để xác định được thì có thể làm các thí nghiệm phá hoại theo mode I; II hoặc III. Sau đó mô phỏng lại trong Abaqus, có sử dụng traction-separation model. Bước tiếp theo là tìm các giá trị K, damage của mô hình mà cho kết quả gần đúng nhất với kết quả thí nghiệm, bằng cách thay đổi các giá trị này, chạy mô hình với mỗi lần thay đổi. Best regards!

@علاءالدينعبدالرحمنحسين 9 ай бұрын

in ENGLISH please the value of kss,ktt and knn whatrepresentst and units ?@@vandangtran6454

@constructionsite8407 3 жыл бұрын

Make a video of brickwall modeling

@vandangtran6454 3 жыл бұрын

hi, good idea

@debron8299 2 жыл бұрын

Hello Sir, How can i get the value knn kss ktt and nominal stress.Do you have example calculate?

@vandangtran6454 2 жыл бұрын

Hi, you can have the values Knn; Kss and Ktt from the experimental tests for the mode I and mode II fracture. Note that the values K are the stiffness of the bond, unit MPa/mm, i.e. the stress per unit of relative displacement (shear). You can find more details on the Abaqus document. The values used in this video aren't from my tests, just an example.