9 ай бұрын
3 жыл бұрын
4 жыл бұрын
Пікірлер
@ibrahimalbaz2595 7 күн бұрын
i have a question regarding the Lx, you said that the girders will move with the column if there is a buckling in X-axis but the thing is, these girders are probably attached to another column maybe, so shouldnt the Lx becomes less same like Ly ??
@firesun 6 күн бұрын
Normally the girts are quite slender, and also simply supported, so will typically provide limited lateral support. Also, the column next door will often be loaded to the state so may be buckling at the same time, so cannot be relied to provide stability. However, there are detailed design methods to evaluate whether members can be considered to provide lateral support.
@ibrahimalbaz2595 6 күн бұрын
@@firesun thank you for your explanation
@Edmund-kg7fp 9 күн бұрын
Thank you
@firesun 9 күн бұрын
Pleasure. Glad it was useful.
@stooncol619 21 күн бұрын
That was really helpful Thank you very much
@MsLuziya Ай бұрын
Are you able to make this lesson in a playlist. Fire design
@firesun Ай бұрын
A number of structural fire engineering videos are provided in this playlist: kzbin.info/aero/PLcXEIpaMKkuq2PknC_UsIErB1igWxPYQ2
@alligodfreyukuni2975 Ай бұрын
Great Explanation,
@user-sr1bd3qo6t Ай бұрын
Thank you for the video
@eldeberryhamster Ай бұрын
It surprises me that there aren't more views and likes of your videos. These are really good.
@eldeberryhamster Ай бұрын
Great explanation!. Thank you, good sir!
@BrownNProud112 Ай бұрын
amazing. just an amazing explanation
@Kiwistoicist 2 ай бұрын
Did you get ly and lx in the wrong way？ the weak axis is Ly which lateral supports only at top and bottom
@firesun 2 ай бұрын
The girts provide lateral support about the weak axis so Ly is shorter.
@collinladao7828 2 ай бұрын
WHERE DOES 10 AND 5 POINT LOAD COME FROM?
@firesun 2 ай бұрын
UDL x span between nodes = 10kN/m x 1m = 10 kN (or half of this for the end bays)
@kyleallan6181 2 ай бұрын
Prof, would the K value for section L3 not be 1.2? The section is laterally and torsionally restraint. If i am correct, a value of 2.5 is for only laterally restrained.
@firesun 2 ай бұрын
L3 is a cantilever. On the right side it is free. On the left side it is continuous with lateral and torsional support. If assumed to be a destabilising load then we end up with K = 2.5.
@brian8838 2 ай бұрын
These videos are really good and well structured. Do you plan to continue with this type of content?
@firesun 2 ай бұрын
You can have a look here and at the channel "Richard Walls" for various structural engineering videos.
@PYRAMIDOFICIAL 2 ай бұрын
Thank you, very good explanation!
@user-lo8nn2ey5o 2 ай бұрын
Thank you! Professor! I love your Video!
@AlanGoswami-nz9lg 3 ай бұрын
Why do these boring idiots discuss cases with hinged/roller joints ??? Virtually every structure is connected using at lease four bolt, thereby making it a moment connection by creating a couple between bolts. The entire structural engineering is so f'ing conservative that we ignore the moments , and waste time and material in bracing them.
@firesun 3 ай бұрын
Unfortunately that is not true. Often in practice bolts are placed within the depth of I-beams to make a base pinned. Also, if a foundation is not sufficiently large enough it will rotate resulting in the base become pinned.
@mileshermon9810 3 ай бұрын
so does this method not work if the enclosure is wood (as b is less than 400). If it is possible, how do you work it all out?
@firesun 3 ай бұрын
The reason it does not work if the enclosure is wood is because your HRR increases massively due to the contribution of the wood. The internal behaviour, burning duration, flame lengths, etc. will all be different from a timber compartment.
@AjayInderchauhan 3 ай бұрын
Figure in front n person in back which type of screen is it
@firesun 3 ай бұрын
Its a light board. Glass screen with light passing through it, that is picked up when you write with special pens.
@annieruth7 3 ай бұрын
Where did you get that model kit?
@firesun 3 ай бұрын
The plastic kit comes from a toy shop. It is a kit for kids consisiing of balls with holes and plastic sticks. Just made it up and adding bracing from string.
@tominmathew344 4 ай бұрын
Sir, can we cut off the Ly as the distance between the channel section if it’s a moment frame.
@richard_walls 4 ай бұрын
Normally the length is taken as the distance from centre to centre of supports.
@mbihnkongo1966 4 ай бұрын
Thanks so much
@arturzych138 5 ай бұрын
That was amazing
@mathurajagadeesh4249 8 ай бұрын
Thank you so much for your lectures. They are a game changer for me and I’m very much benefiting from it 🙏🙏
@mohammadrashid9350 8 ай бұрын
Wonderful presentation and a great content. Thank you
@johan2603 8 ай бұрын
Brilliant video indeed. It sad that we get so uses to it living in South Africa. This is so sad, thank you for this video. We have so much work in South Africa making it better for everyone.
@satnamchana 8 ай бұрын
If my Ted (equivalent time) is 35.51 mins so below my required resistance of R60 (60 mins) does that mean the beam fails?
@firesun 8 ай бұрын
It depends. If you calculate that your beam needs 35.5 minutes of equivalent resistance based on the room geometry, and you provide 60 minutes then you are fine. 60 minutes would normally represent the code requirement, whereas an equivalent design time of 35.5 min represents an updated requirement. Hence, they are requirements based on different assumptions, rather than one being pass or fail.
@yipfukeung8819 8 ай бұрын
Great, Professor! You are my hero, cant understand the concept without you
@ranjanty 8 ай бұрын
Hi, could you please help me? I have a 48inx24in stainless steel table with tubular legs that are 32.75inches high. I want to increase the weight capacity which is 500 something lbs. If I fill the legs with concrete and a piece of rebar would that increase the weight capacity of the table? Maybe to 800 lbs. I'm 70 and I'm no longer able to figure it out. Thanks to anyone who chooses to help ❤
@firesun 8 ай бұрын
Sorry, my brain does not work as well in lbs and inches. Strength is often governed by member capacity and also connections. Hence, if you strengthen something you also need to ensure that the connections between members are sufficient. As a rough rule of thumb if you take the area of concrete at around 40% of the strength, say 20 MPa for a low quality concrete, and add on strength of the rebar at 60% of its yield strength you have a ballpark estimate of the capacity. 800lbs is not that much load for a steel and concrete structure, especially if there are 4 legs.
@georgen9755 9 ай бұрын
Thanks to Sir Helms Sir Isaac Wait
@magurwakomborero7541 9 ай бұрын
Thanks for this set of video series , i learnt a lot
@mbiat1234 9 ай бұрын
hello i came across your channel ... looking for advice... omy, i was asked by building control regarding wind bracing on a flat roofed steel frame 5250mm in height . each bay 4900mm. designed the cols and beams with moment joints, the council refused it saying laterally unrestrained...
@firesun 9 ай бұрын
It is possible to design a structure with moment resisting frames rather than bracing. However, it needs to be ensured the structure is braced in both directions. For minor axis bending that can be a problem unless a separate frame is added. However, without knowledge of the system discussed it is just speculative.
@mohammadrashid9350 9 ай бұрын
Iam from India. Can I be considered for the Bursary?
@richard_walls 9 ай бұрын
Unfortunately the bursaries for this year have closed. However, Indian students are equally welcome to apply for bursaries when they are open. We shall advertise more next year.
@SamsonAAasa 9 ай бұрын
Please can I be considered for application fee waiver?
@firesun 9 ай бұрын
The application fee is not expensive, just a few hundred rand. We have advertised bursaries for full-time studies. We don't have bursaries for part-time students as they are typically sponsored by their companies or local countries.
@georgen9755 9 ай бұрын
column on single strorey
@georgen9755 9 ай бұрын
previously faculty ....................now at mat
@survivorhomesteading2960 9 ай бұрын
I'm designing the binding steel around a glass fabrication melting furnace (furnace is about the size of a house), and binding steel can be exposed to temperatures as high as 1000°F. I was planning on simply using the material strength reduction factors listed in a AISC's Table A-4.2.1 (the "red" steel book governs our design in Tennessee); however, I'm getting some hesitation from the engineering subcontractor I'm working with. They don't think we can use these reduction factors because they believe these factors were only meant for a "temporary "fire condition and not a prolonged, continuous glass melting furnace campaign that can last up to 20 years. I reread the code, and I don't see anything about these reduction factors being restricted to a certain "duration" of fire... I only see a note that says as long as the yield strength is below 65 KSI, the factors in the table are applicable. Do you have any insights on this, or do you think anyone in the AISC community might?
@firesun 9 ай бұрын
When I worked in practice we did lots of glass furnaces at my old company. Few tests have been done on long-term strength reduction, where steel has been exposed to high temperatures for months, but spending time on Google scholar you might find something. The data available is probably suitable for long-term, but has not been verified in long-term tests. At a constant temperature I cannot see a chemical change occurring based on duration of testing. However, of greater concern is restrained thermal expansion if members cannot expand. That induces very high forces. Hence, my suggestion would be to ensure members are not restrained from expanding through careful connection detailing. However, may be sensible to used slightly reduced factors for the reduction factors based on uncertainty regarding long term effects.
@shelbyphillipson4336 9 ай бұрын
Where does sqrt 2 come from?
@richard_walls 9 ай бұрын
1 / sin(45 degrees). It is to convert the diagonal force to a vertical force for sum of forces at a node.
@yokeleetan8525 Жыл бұрын
nice one... am wondering if a thin intumescent spray on steel duct can provide fire resistance in terms of insulation say 60mins using standard fire curve in furnace.
@firesun Жыл бұрын
You are unlikely to be able to turn a single plate of steel into a fire wall with insulation resistance using only intumescent. The steel normally fails insulation criteria before the intumescent has even activated. It is for structural resistance, and not compartmentation, that intumescents are applied
@Civillivic Жыл бұрын
Million worthful ❤
@GenaEnSamIAm Жыл бұрын
Thank you for an awesome refresher 😊
@user-iu2jl4mn7b Жыл бұрын
Thank Man . Wonderfully Explained
@ahmedyaqub2377 Жыл бұрын
How can I prevent cracks in partition walls due to deflected steel structural beams' interaction?
@firesun Жыл бұрын
Stop the beam from deflecting (i.e. stiffen it) or isolate the members from each other.
@ahmedyaqub2377 Жыл бұрын
@@firesun Regarding isolating the members from each other is there any code mentioned that, like IBC or AICS Standard, Please help me
@firesun Жыл бұрын
@@ahmedyaqub2377 - You simply need to install a soft material that can accommodate the movement, and keep the wall and beams not connected to each other.
@ahmedyaqub2377 Жыл бұрын
@@firesun Dea Sir, there is a controversy in our company that insulation is not required and it is possible to make the non-loading partitions directly contacted with steel truss without separation, so I need a paragraph in the code that stipulates that the isolation must be achieved
@firesun Жыл бұрын
@@ahmedyaqub2377 You will not normally find this in a code. However, if a steel struss moves more than a wall can allow then the wall will crack. It is based on physics rather than codes.
@iniekpenyong2842 Жыл бұрын
THANKS SO MUCH, PLEASE IS THERE ANY DESIGN CODE THAT SUPPORTS THISE METHOD?
@firesun Жыл бұрын
Nope. Based on fundamental mechanics and structural analysis, rather than a code. However, most code guidelines follow such an analysis. Go find a structural engineer with grey hair and they will show you more useful techniques like this.
@learnmathwithprivilege Жыл бұрын
What is the effect of flange restraint in the middle of the section when we have a uniaxial bending .
@richard_walls Жыл бұрын
It prevents lateral torsional buckling (for Mr) and flexural buckling (for Cry).
@davepowell7168 Жыл бұрын
9.11 was a very progressive example. The deliberate sacrifice of innocent civilians is revolting Thanks for the insights from this apolitical channel
@Alias102. Жыл бұрын
Would the effective length factor K change if the column were to be restrained say twice or once along its length.
@user-qy3zo6dz5v Жыл бұрын
Thank you for this helpful video. I had a question about destabilizing load. In the cantilever portion the load is on the tension flange and bottom flange is having bending compression. Will the load have stabilizing or destabilizing effect being on tension side?
@firesun Жыл бұрын
SANS 10162-1, which is probably the most codes, defines a destabilising load as being on the top/tension flange.
@firesun Жыл бұрын
Specifically in terms of cantilevers
@nicolasjativa1441 Жыл бұрын
So well explained!!!
@Szhihihihihihi Жыл бұрын
Thank you !
@JuglaresMBG Жыл бұрын
Brilliant video. Where did u get that frame model? It's really useful.