Back to some reinforced concrete analysis and design. Here's a video on calculating the design moment strength of a doubly reinforced concrete section. Enjoy.

@salwan6153

10 жыл бұрын

Yessss thank you , but this video does not open...

@yusufb777

6 жыл бұрын

when we are analysing the basic reinforced concrete beam (which reinforcen on only tension) i think we dont need to calculate ß1 and Cna because when we use horizantal force equalibrium we got [Fc=Fs and then fc'x0.85xaxb=fs'xAs] and we are avaible to calculate a direcly. Why we have to calculate Cna and ß1???

@samraahmed296

5 жыл бұрын

Screen is completely green I can't see video there is only audio.... What is the issue???

@theuknowns1766

5 жыл бұрын

wheres the part 2???

Bro, I love your work! You make something so complex becoming so simple and easy! I am rocking all my exams with because of you! Thank you VERY, VERY, VERY MUCH! I always watch the advertisements so that you rock as well $$$!

structurefree... you the real MVP! Very concise, detailed examples. Also, thanks for keeping the enthusiasm levels high. Respect

@structurefree

8 жыл бұрын

+Amir Habibi Thank you for your comment and kind words! I love being compared to internal loading (moments - M, shears - V, and axial load - P).

@amirhabibi9121

8 жыл бұрын

ayyyy... he's got jokes too!!? you the man!! haha

I am a structural engineer and I must tell you that I love the way you develop your videos and the tremendous structurefree concept !!! I congratulate you. I wish you do video of Shear Walls, Deep Beam, Coupling Beams or piles would be GREAT! I keep watching the videos and they are excellent !!!

yo i love ur attitude u are the man

every time I get stuck in concrete design you have just the perfect video that fixes it. It's like magic! Edit: you should really consider activating the tip jar or starting a patreon. Just saying. You've saved my a** enough to warrent $20

@aldojansel9439

5 жыл бұрын

20k?

thank you so much you make it fun and I love your explanations

Oh my god. I love this channel.

Can you do one thats doubly reinforced but Mu, f'c, and fy is given and you have to pick an As and A's?

This guy rocks!

I can't thank you enough for doing these videos, they are incredibly helpful! I have one question though: if cna turned out to be less than 2.5", making ε's negative...would you have proceeded with the calculations or would you have re-designed the beam? I have encountered this issue especially when working with doubly reinforced T-beams.

Thank You! You are so educative!! :))

Thank you 🌸 Fun and useful ✨

You're my favorite online tutor. I'll love you forever if you post a solution to a problem like this exactly, but instead, we are given the beam dimensions and d and d" and the moment the beam is holding, and we have to find what is As and As'.. Please :(? I'm lost on how to backtrack to find the amount of steel needed...

Hi StructureFree. Question: How does the stress-strain curve for doubly reinforced concrete beams compare to that for singly reinforced beams? Do the same concepts (ie Stage 1, Stage 2, Stage 3 as explained in your previous videos still apply? How does the compression steel play into this? Thanks

Is it possible to use the first moment of area to find c (neutral axis) and then determine whether or not the strains at Eu 0.003 are greater than fy/E (0.0021 for grade 60) so that you can determine yielding before doing the force analysis and Mn calc?

Very helpful video. Thank you!!! I just have a question. Can you actually use this beam? The reason why I am asking is because the strain of the steel in the compression area is less than .004. I thought the minimum strain value for the steel that we can use is .004 based on ACI. Or that only applies in the Tension side?

who is giving this guy thumbs down?? These videos are great man

@mkayzondy

4 жыл бұрын

maybe they were watching the video upside down, so they thought it a like thumb🤷‍♀️

can you please tell me what table from ASI / A did you use to determine E s = 0.003 ???

Love the procedure. Used it on a HW problem and with the given data in my problem, (y-bar/2)-d' is a negative number. I'm thinking the problem may just be poorly conceived, but even so, I should still get the correct moment calculation even if the Cs has a negative contribution, to Mn, yes?

the Cc in this part should be 0.85fc'(ba-As') since we need to subtract the part of compression concrete in the account of being cover by the As'. Is it right?

@jorgehurtado7738

5 жыл бұрын

Right

Thank you

Can you have a sample for irregular(composite figure) cross section doubly reinforced beam? Thanks...

helpful to me..

Please place a link to part 2 in the description.

great. Which software are u using for your writing?

thanks help alot

awesome

can u show the derivation of quadratic equation "c" when the steel is not yielding

This very same Section also suits Singly-Reinforced Design. What then is the Boundary between Singly-Reinforced and Doubly-Reinforced Sections? Is it if the Maximum Moment Capacity at Ey = 0.005 of Singly-Reinforced Section is still Less than Mu?

thank you so much ... please ,,,I want know what specification of hidden concrete beams in U.S code ? best regards ,,,

Can you please post a link of second part of the problem? "calculating nominal moment, strength reduction factor, design moment strength". first part has been extremely helpful in understanding the concept. Thanks heaps.

@structurefree

9 жыл бұрын

+Gagan Kataria Thanks for commenting! I'm glad to hear the video was helpful for you. Looking at my reinforced concrete playlist may help. In any case, the link is below: kzread.info/dash/bejne/d4ac0beFitO9mNY.html

Thanks

if you want to design doubly-reinforcement, and if you find out that your steel at the upper edge hasnt yield , you will then need to solve 3rd degree polynomial to find the location of the neutral axis?

Quick question. How do you get the moment capacity of a beam that hasn't reached compressive strain of 0.003. Compressive strain less than 0.003. Thanks.

@structurefree

8 жыл бұрын

The concrete in compression (at the very top of the beam in this example) has reached a strain of 0.003. The strain at the compression steel layer is what is less than 0.003.

the best

Will you be doing some design videos using eurocode? :)

thank you

@structurefree

8 жыл бұрын

You're welcome.

What if As and As’ are equal, Cna will be zero right?

Namaste!

which program do you use for writing??

@structurefree

9 жыл бұрын

Goran Adil i use windows journal.

What if tensile has not yield, what might we do ????? At the same time, what if As and As' are euqal each other, what can we do? Especially, if there are both of them what i said in same question, what can we do? Please help me, because our teacher ask us like what i mentioned in the exam. I m looking for answer about this question, please help!

Sir what if Assumption 2 is the one thats invalid not the Assumption 1, what are we gonna do? Hope you will answer my question. Thank you

what if we use the same number of steel bars on the top and the bottom? Cna would be zero?

@structurefree

4 жыл бұрын

You still have to use equilibrium to determine CNA. CNA would not be zero.

Just out of curiousity, have you read Dr. Akthem Al-Manaseer's book?

@gabrielledang7343

5 жыл бұрын

LOL Hi Hien hahaha

pls upload videos about shear and diagonal tension.. pls! thnx

If you have time, and if you want to, you could do a video on it, I know a lot of people struggle with the slightly more complex frames

@structurefree

10 жыл бұрын

I'll add analysis of portal frames on my to do list.

@harvest100x

10 жыл бұрын

structurefree that would be really great. thanks heaps.

hello sir, first of all i am sorry because my English is bad. I want to ask you, how to calculate the moment if my neutral axis (Cna) is above the compression steel?

what it is mean if the beam is compression controls or tension controls? -Civil Engineering Student

@kirkramirez7077

9 жыл бұрын

if is tension control, phi factor is 0.9. if is compression control, phi is .65... to be tension control the tension steel must reach at least .005

why is there no tensile force in the concrete, but there is a compressive force?

hopefully this helps me enough so my midterm isnt completely homeless

goooooooooooooooooooooooood jooooooooooob

My professor design a cross section with 2 hollow, asking us to find a maximum positive moment of it. Are him crazy?

Wow

genius

Shortcut to part 2: kzread.info/dash/bejne/d4ac0beFitO9mNY.html

dk

plz dont make stupid sounds, because thats really annoying, and losing focus

dont you want both steels to yield...!! is that a safe structure if the top steel hasnt exceeded epsilon y. great vids and would greatly appreciate a respsonse. danka x