Great question! the basic mechanics equations like tau = VQ/Ib and the transformed area method (Es/Ec) are only applicable when the material remains linear elastic (i.e. the strains do not exceed the proportional limit) and the stress profile remains linear. Force equilibrium works in all stages of material behavior in a beam, even when the material behaves nonlinearly...as in the instant before concrete crush or ultimate RC beam behavior. Thank you for your question and kind comments!
beta1 is a factor in the whitney stress block. it helps to locate the resultant of the compression force in a reinforced concrete section. every reinforced concrete design textbook has an explanation of the relationship between beta1 and fc'.
Calcs we find the neutral axis using the area of concerted and the equivalent area of steel (using Es/Ec) and in other we find it using force equilibrium!
there are a few options here. you can use superposition for the compression area or calculate the centroid of the T-shaped compression area from the extreme compression fiber. hope that helps.
Thank you so much for your efforts and for your content ... i enjoy every single lecture truly ... i see your explanation/way of solving problems easier than of my prof. at the univ. ... :D much more interesting much more fun actually .... my exam is tomorrow sorry for that but i was missing an explanation or a problem solving for the shear in reinforced concrete beams ... if or if only you could help me out by either problems you already solved or even point me out to a simple video explaining it. :3 thanks.
Hi, I understand that the neutral axis is the axis along the length of the beam which remains unstressed. Which means I will need to find it using force equilibrium. However, when we calculate the shear stress across a section using using t=VQ/Ib we assume the neutral axis is at the centroid! What I want to ask is why in some call
Hi again so If I have calculated the cracked second moment of inertia and I want to use it in tau=VQ/It . The area I should use to calculate Q under neutral axis (assuming under the neutral axis is the tension zone) is that of the transformed area of steel only?
+structurefree so that is to say the centroid is: Cc=ΣA*c/ΣA = (36"*4"*2"+16"*X*(4+X/2))/(36"*4"+16"*X) Where X is the distance below the flange the compression zone extends. Please Confirm, and thanks for being awesome
+BendyBus Song epsilon y is the yield strain of steel which can be calculated from hooke's law. epsilon y = f_y/E_s. For grade 60 steel, it is 0.00207.
the area in compression would be a T-shape, you'd have to calculate the centroid of a t-shape to determine ybar (the location of the compression force resultant)
I used this method in my exam and the teacher didn't accept it and only gave me one mark out of 8 for the question and he was so rude with me and told me to pay attention so I can solve using his method 😳
Deivssz no he didn't determine a specific way to answer in the question .. I believe he was mean to me because I didn't take notes in his class and he pointed that out several times .. I'm not sure but he was so mean during the entire semester with me even out of class !!!!
Hello sir I have single house 2 floor my question how I can calculate the concrete T beam for roof ceiling ? The length of building 13.5 meters and width 15 meters thank you
Dude. I was not prepared for such a perfect example to one of my homework problems. A real lifesaver. I love the internet.
Exactly and I love how the equation was explained at the end so if you got it logically you can derive the equation yourself. Excellent! 👍
Btw you are a great teacher and one of the few ppl I actually enjoy listening to when they speak about design and analysis. Many thanks
Thank you so much Sir ,
I was depressed about PRC but your video gave me confidence .
Hey man, just wanted to say thanks. Your videos are clear and concise, and are truly great study tools. Keep on keepin' on.
Great question! the basic mechanics equations like tau = VQ/Ib and the transformed area method (Es/Ec) are only applicable when the material remains linear elastic (i.e. the strains do not exceed the proportional limit) and the stress profile remains linear. Force equilibrium works in all stages of material behavior in a beam, even when the material behaves nonlinearly...as in the instant before concrete crush or ultimate RC beam behavior. Thank you for your question and kind comments!
Thank you for being such an awesome teacher.
🔥
Yo, structurefree! Thank you so much for your videos. This video saved me on a RC problem that had puzzled me all night. You rock!
You make me feel excited to learn civil engineering physics dude :)
Out here studying for my SE exam watching Structure Free Learning 10/10
I wish you had a video about designing process of the T beam
anyway, you are a great teacher and an engineer.
beta1 is a factor in the whitney stress block. it helps to locate the resultant of the compression force in a reinforced concrete section. every reinforced concrete design textbook has an explanation of the relationship between beta1 and fc'.
Calcs we find the neutral axis using the area of concerted and the equivalent area of steel (using Es/Ec) and in other we find it using force equilibrium!
there are a few options here. you can use superposition for the compression area or calculate the centroid of the T-shaped compression area from the extreme compression fiber. hope that helps.
i thing i love him more than the internet...
Thank you very much. Also i was wondering if you can make a video where the compression area is both in the Flange and web ?
There is now a video covering this. See: I-shaped RC Beam Design Moment Strength - Reinforced Concrete Analysis. Hope this helps all!
thank you soooo much! The video is very pracitcal!
Awesome man! love your videos!
Thank you so much for your efforts and for your content ... i enjoy every single lecture truly ... i see your explanation/way of solving problems easier than of my prof. at the univ. ... :D much more interesting much more fun actually .... my exam is tomorrow sorry for that but i was missing an explanation or a problem solving for the shear in reinforced concrete beams ... if or if only you could help me out by either problems you already solved or even point me out to a simple video explaining it. :3 thanks.
Hi, I understand that the neutral axis is the axis along the length of the beam which remains unstressed. Which means I will need to find it using force equilibrium. However, when we calculate the shear stress across a section using using t=VQ/Ib we assume the neutral axis is at the centroid! What I want to ask is why in some call
Do you have an example of this type of problem if the neutral axis is below the flange
thanks for the video man! extremely helpful!
I couldn't find it, but do you have a video showing the calculation of the effective flange width (be) ?
Hi, could you please make en exemple of RC T-Beam, when the compression fall below the flenge height? if a > hf
Please make a video on torsional design of RCC rectangular and flanged beam...
beta1 is based on fc'. if fc' is less than or equal to 4 ksi, beta1 = 0.85.
how to find effective depth of flanged beam if the beam have unequal dia bars
Hi again so If I have calculated the cracked second moment of inertia and I want to use it in tau=VQ/It . The area I should use to calculate Q under neutral axis (assuming under the neutral axis is the tension zone) is that of the transformed area of steel only?
you're a lifesaver
In the real world setting, how is S (the spacing between T-beams) decided? Any structural codes for this S or the designer has the liberty to decide?
What happens if Acc is bigger than the area of flange?
gross or cracked moment of inertia?
what if the value of a is greater than hf? plss solve some problem with this case. thank you sooooooooooooooo much
Your videos really helped me more than my Dr.
How can i design steel with Given : fc,fy,Mu and Es ofc with d,b,h ??
bf unkown
Very good explanation (Y)
thanks a lot ......this video is to helpfull
What do you do with reinforcements on both the top and bottom
analyze like a doubly reinforced beam
@@structurefree thank you do you have T-Beam with double reinforcements on your channel
I have question how can we find moment of inertia for such T design???
Im sorry if Im annoying you with all these questions but I don't know who else to ask! thanks again
what's happens if the compression area consist of both (flange And web). please Make a video for that
You would have to calculate the centroid of the compression zone.
+structurefree
so that is to say the centroid is: Cc=ΣA*c/ΣA = (36"*4"*2"+16"*X*(4+X/2))/(36"*4"+16"*X)
Where X is the distance below the flange the compression zone extends.
Please Confirm, and thanks for being awesome
So is Mn the same value at the midspan of the beam?
Yes, assuming that you still have compression at the top from the applied loading.
I though we find beta1 based on fs? how much would beta1 be if my fc'= 3 ksi please? I'm so confused now :(
what happens to Mn if es
Technically the beam would be illegal. But you could calculate Mn, you will need to incorporate Hooke's law.
Can you not just find your value "a" and check if it is less than hf, (flange height)?
So what's the value of epsilon y?Sorry if it's a dumb question.
+BendyBus Song epsilon y is the yield strain of steel which can be calculated from hooke's law. epsilon y = f_y/E_s. For grade 60 steel, it is 0.00207.
structurefree Ok thanks! Makes sense.
Hi thanks for your videos . Understand a lot but im hoping too fpr examples in metric system or si units.
thanks man u r great :)) A#10 is equal to 1.227 in^2 not 1.27 in^2 right ?
PEACEFUL MIND area of a #10 bar A = 1.27 in^2. The diameter of the bar has the same magnitude = 1.27 in.
How about if Ac is Greater than Af?
and what if a somewhat covers a bit of the web's Area?
the area in compression would be a T-shape, you'd have to calculate the centroid of a t-shape to determine ybar (the location of the compression force resultant)
I used this method in my exam and the teacher didn't accept it and only gave me one mark out of 8 for the question and he was so rude with me and told me to pay attention so I can solve using his method 😳
+Lina J 😱
Deivssz no he didn't determine a specific way to answer in the question .. I believe he was mean to me because I didn't take notes in his class and he pointed that out several times .. I'm not sure but he was so mean during the entire semester with me even out of class !!!!
Can you send me the size of beam if the room dimensions is 4.5x380sqm
Hello sir I have single house 2 floor my question how I can calculate the concrete T beam for roof ceiling ? The length of building 13.5 meters and width 15 meters thank you
+Amee Hassa congrats on your house....why you gotta brag? Just kidding. You should start with your loading and load factors.
You mean we can not make it for built house 2 floor every floor 250 sqm?
Can you make a video intensity about electricity is not working in food intensive distribution moment and
FYI, Thank you very much :)
I just wished you worked in mm, m, N/mm etc!!
Harry D i'll try to do some structural design in si units. i'm in the u.s. and our design specifications use fps as the primary system of units.
I hope too
How is possible is not changing to you notice any how can I will status in this is the electrical
very. thanks. for. u.
beta 1=0.85
it is so intense a difficult but it is not easy it is it is very intense another system for you will be tracked minister that is not
OK I will join you after sometime that is not apply to you thanks