Really great. Thanks dear

THANK YOU

GREAT

Nice tutorial..!!!

Very interesting work and helpful. I have to need external CFRP tendons are anchored at the two end of the specimen and pitted with deviators at mid-span

@vandangtran6454

6 ай бұрын

Hello, this video, has been on my list, in the link below may help you: kzread.info/dash/bejne/f39npZZsfJfJdrA.html

Continue making such great videos, can you do a PT slab

@thecitizen9747

2 жыл бұрын

Yeahh that will help us a lot!

Thank you! I was wondering if it can be done for polymers as well. Im doing research on unbonded post-tension in 3D printed beams (z-direction)

@vandangtran6454

2 жыл бұрын

Hi! yes, you can.

Please make a tutorial on prestressing of steel girder.

@vandangtran6454

3 жыл бұрын

Ok as soon as possible :)

@madancmaurya328

3 жыл бұрын

@@vandangtran6454 thank you..!!!

our appreciation for your effort ... really, we benefited from your educational videos ...plz dr . can you inform me how can define and modeling frp-bars strengthening RC beam as near surface mounted techinque.

@vandangtran6454

3 жыл бұрын

Hi, i can't tell me in one comment. as i have time, i may provide a video about that. But you should send me a dimensioning of your RC beam if you can

@abbasj-d6951

3 жыл бұрын

@@vandangtran6454 Thanks and appreciation to you; the case describe as : simply supported RC 3000mm length and cross section (250x400)mm reinforcd by two bars 16mm (top and bottom) with stirrup dia 10mm @200 strengthening by one of CFRP-BARS dia 12mm (using 3d cohesive element ) groove demension (15*20)mm. (The rest of the information can be assumed) Best wishes to you ... and I apologize for taking part of your time

Thanks alot, Please can you advise me how can simulated the partial damaged in prestressed strands in ABAQUS as we have (me and my colleaques Abbas who sent you the problem befire) same issue....and we appreciate you assisstance

@vandangtran6454

3 жыл бұрын

Hi, I suppose that the partial damage mentioned in your comment is just for the steel strands. So, in the simple way, you should assign the elastoplastic damaged response to the partial strand. Many response of the steel exists. I recommended: "Classical metal plasticity" or "Johnson-cook plasticity" existed in the Abaqus. all other steps may be followed by this tutorials video. if you have something stuck, I can help you.

@hayderqais3197

3 жыл бұрын

Thanks a lot

How can we model prestressed concrete if we don't have models to simulate plain concrete properly??

Hello Sir, Would this method work for a parabolic shaped tendon?

Dear Mr. Tran, at what 00:00 did you add the tension load or BC to the tendon? Thank you!

@vandangtran6454

2 жыл бұрын

Hi! for the pre-tension bar, once the tension load is applied, the steel bar must be embedded in the concrete beam (contact/embedded). That is how to give the BC for the pre-tension steel bar.

Hello Mr. Great work and very helpful I have 3 questions if possible : In order to define the curvature friction can you please give me a way ? And the anchor retreat of the post tension ? Plus I a trying to get the deflection as accurate as possible for this kind of beams so is there a meshing technique you advise of ? Your help is much appreciated and thank you sir

@vandangtran6454

Жыл бұрын

Hello, you have to simulate the cable as a solid element or as having a surface. There should be two contact surfaces, one of the concrete part and one of the cable. and the contact with the friction behavior of two surfaces should be defined. To recover the deflection, a point in the middle of the beam should be created for the model.

trong mô hình này Đăng khai ứng DUL là ứng suất ban đầu ở trong cáp, vậy thì ở các increment ban đầu ở step 1 dầm sẽ phải có ứng suất ban đầu chứ

@vandangtran6454

3 жыл бұрын

bài này e chỉ đề cập tới việc mô phỏng thép DUL trong kết cấu bt thôi ạ. Đúng là có lực nén trong bê tông, nhưng có thể coi như lực nén này đã tính vào trong cường độ fc hiện tại của bê tông khai báo trong mô hình, nghĩa là ví dụ fc (ko có thép DUL) =40 Mpa, thì fc (có thép DUL)=40-lực nén do thép=fc khai báo trong model.

Thank you

Hi, I did not see in the video when you applied the tension to the tendon.

@vandangtran6454

Жыл бұрын

Hello, at 35:29 you see that

I have somequestions for my senior project in prestressing cold-formed steel beam. I created predefined fields for the initial and final temperature for the cable and run in static,general. But when I look at the strain or temp at a node on beam element it did not transfer the thermal expansion, how can I solve this.

@vandangtran6454

Жыл бұрын

Hello! I don't know how it works exactly without looking at the model. But when you apply the thermal, pay attention to the type of element, and the boundary conditions! good luck

at 35:32, there are already two predefined fields and then you are showing third one. please explain the first two.

@vandangtran6454

Жыл бұрын

Good morning, you have well noted! but what I wanted to say is that these first two "predefined" must be deleted and have not been taken into account. They are just tests that I made during the simulation. but I forgot to delete them when I made the video.

How did you apply prestressing to strand? I didn't see it

@vandangtran6454

2 ай бұрын

Hello, I've shown first the case where the bar is not prestressed, and then the prestress, so you can see at 35:37

dear /dr please can you inform me how can simulate the post-tension member subjected to partial damaged strand under static super-imposed load

@vandangtran6454

3 жыл бұрын

i need more information but i think first you may need a complete damaged response definition for the steel strand

@abbasj-d6951

3 жыл бұрын

@@vandangtran6454 thank you sir. my case is about post-tension bridge girder (rectangular section) subjected to cut of about 0.25 strand ... so if the girder with 4 strands that mean 1 strands will be damged and the i will strengthening by nsm-frp ....but i dont know how can simulate the damage ....

@hayderqais3197

3 жыл бұрын

Thank you so much, and we are looking to your responce with appreciation

Hi Sir, i'm a student, and i'm trying to use this program for an experiment. Is it possible to pull the cable and then lock it at the ends of the beam so that it follows a temperature load? (in the elastic phase )

@vandangtran6454

2 жыл бұрын

Hello, I think it can be done with a complete 3D model. That means the cable must be simulated as a solid element. So we can fix the cable at the end and put a thermal load. Good luck!

Hello dr tran, can i ask your help for my thesis. I have problem with numerical model. Its about bond-slip on reinforcement concrete. How i define the cohesive contact for surface interaction rebar and concrete?. Thank you sir.

@vandangtran6454

Жыл бұрын

Hello, this is an example: kzread.info/dash/bejne/kaxqkpJ_abHgqs4.html You can use "surface-based cohesive behavior" (see more in abaqus documentation)

Hello. I was not able to understand how the error was been resolved ? The video is not showing the error elimination of property of 22 elements. Can you please let me know how to resolve the error ? Thanks in advance.

@vandangtran6454

Жыл бұрын

Hello, I assume you are referring to the error regarding the property of the steel to be defined. So, steel is put as a bar-type element in 2D; therefore, you should define a material corresponding to this type of finite element.

I got the error related to CDP. Kindly share how to resolve this. "DURING THE CONVERSION FROM CRACKING TO PLASTIC STRAIN Abaqus FOUND NEGATIVE AND/OR DECREASING VALUES OF PLASTIC STRAIN. VERIFY THAT THE DEGRADATION DATA UNDER *CONCRETE TENSION DAMAGE IS CORRECT" Thanks

@vandangtran6454

2 жыл бұрын

Hi, the error may concern to the data of the tension that you have used for defition. Noted that all values must be positives.

Hi sir, very extraordinary tutorial video, I would like to ask how to add reinforcement bars in this beam? Can you tell me via email if it is available?

@vandangtran6454

2 жыл бұрын

Hi, you can find how to do in this video : kzread.info/dash/bejne/nmSBpMeQgLvFk9I.html

Dear Dr I have a question , during my model RC wall exposed to cyclic load, I noticed that CDP model gives me inaccurate hysteresis results , why? how to overcome this problem?

@vandangtran6454

Жыл бұрын

Hello, it's a bit difficult to tell you exactly what the problem is without looking at your model. but as a first step, it would be necessary to identify the parameters of the real behavior of the concrete, including the stiffness recovery parameter which allows modeling the cyclic behavior of the concrete with the dissipation of the stiffness (important parameter). good luck

@amrmasoud5580

Жыл бұрын

@@vandangtran6454 OK, This in case of well steel reinforcement, but, in case of PINCHING effect, Abaqus and CDP cant model this phenomenon besides, CDP cant account the shear reduction effect.

Sir you jumped directly to results page without solving error i don't know how sir... please update

@vandangtran6454

3 жыл бұрын

do you mean :"22 elements have missing property definition"? ok! that is the problem about the element type of the steel strand. so! you have to define the element type for the steel strand as "truss": mesh/Element type/Family: truss

Do you have a website or something to contacte you

@vandangtran6454

Жыл бұрын

Hi! you can find my email in "ABOUT" of my channel youtube.

Am i the only one to not see where he applied the prestress??

@vandangtran6454

2 жыл бұрын

you can watch from 35:28

@thecitizen9747

2 жыл бұрын

@@vandangtran6454 just saw it. Thanks a lot Sir. Can u please make another prestressed concrete video but this time for a frame structure or prestressed steel structure?

This is one of the worst video I have ever see! Too many mistakes. It seems the author is learning how to solve the problem. I don't see the anchors at the end of the wire.

@vandangtran6454

Жыл бұрын

Thank you for your comment! I see that you have carefully watched my video and found some mistakes in your way. but I would like to ask you: why do we need an anchor in the case where the steel cables are embedded (fixed) in the concrete?

@mariogalindoq

Жыл бұрын

​@@vandangtran6454 You need anchors at the ends of the cables to model the fact that the cables are stressed when they are free (not attached). Subsequently, concrete is injected into the sheath, which is when the adhesion between the concrete and the cable occurs. It is also possible to work with non-adhered cables, so it is mandatory to have anchors at the ends of the cables. In any case, the stress state of the concrete is strongly affected by the anchors at the ends of the beam. The way you have modeled the beam corresponds to that of prestressed concrete, this is when the cables are first stressed before the concrete is poured, however this is not normally done with curved cables. So you have three different cases: 1) The cables are tensioned without adherence and later the sheaths are injected to produce adherence, 2) The cables are stressed without adhesion and remain so during the useful life of the beam, 3) The cables are stressed before the concrete is poured. The three cases have different results in the stress state of the concrete. For cases 1 and 2 it is necessary to model the anchors at the end of the cables. Thank you for your response to my somewhat aggressive comment. My apologies. Sometimes I write without thinking. Anyway I encourage you to continue with your videos.