DO NOT design connections before understanding this

In this video I go through a little bit about fixed and pinned connections as well as rigidity of supports.
I also show you an example of a stiff beam, flexible column, flexible beam and how the stiffer elements will attract large portion of the internal forces.
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[@rakshith4398]

Glad I ran into this video before starting to design connections. Thanks!

[@bengthebrazilianengineerinAus]

Awesome. Thanks for watching :)

[@edmarferreirajunior724]

A rigid connection is by definition a complete connection, as there is no degree of freedom in a rigid connection. But a rigid connection is also a continuity, in this case, of stiffness between the elements in the connection. You demonstrated this very well by modifying the beam height in the portal frame examples. And that's exactly the problem with bolted connections. The holes required for bolts insertion reduce the amount of material in the section, which in turn reduces the section's moment of inertia. There is, therefore, a local reduction of stiffness in the section, making it more difficult and expensive to achieve a truly rigid connection with bolted connections. When we design bolted connections, would be more apropriate to consider semi-rigid connections. Excellent video, by the way. Thanks a lot!

[@bengthebrazilianengineerinAus]

Hi Edmar, thanks for taking the time to write this comment. Very well said. Thanks :)

[@edwinclement8962]

Great video! Just trying to get back into design after years onsite and been trying for months looking through books and videos to understand the idealisation of structure supports! Cheers man!!

[@bengthebrazilianengineerinAus]

Hi Edwin, Great thing you started onsite. You've got the advantage of knowing and seeing how the structure is put together. The design skills will come with time and study.

[@edwinclement8962]

@@bengthebrazilianengineerinAus Sadly, my engineering experience is playing around in the dirt and getting things to compact rather than structures. I've got my working holiday visa for Aus heading out in June. In that regard, the typical residential housing video was bang on. Cheers, Ed

[@pcarol9324]

The video is short, clear and high value for structural study. Thanks Gabriel!

[@bengthebrazilianengineerinAus]

thanks :)

[@lukexin7441]

Amusing and easy to understand, these concepts in this video are normally confusing engineers. thumb up !

[@bengthebrazilianengineerinAus]

Thanks Luke. :)

[@M1BR89]

Nice video .. clear and simple 👍🏻

[@shm1883]

This one video would have got me through my first job interview with flying colors!

[@bengthebrazilianengineerinAus]

haha what did you get asked in your job interview?

[@MariaSantos-l4n3c]

Great video! Thank you for sharing! Loved the gummy bear example,It made it very easy to understand.

[@bengthebrazilianengineerinAus]

Thanks Maria :) Who doesn't love gummy bears

[@luiseduardopaesborges5736]

Cara, como é bom ver seus vídeos. Conteúdo que realmente agrega e ainda aprendo termos técnicos em inglês! Parabéns! (Dude, your videos are awesome! Really valuable content and I improve my english! Congratulations!!)

[@bengthebrazilianengineerinAus]

valeu meu brother. grande abraco

[@sinarongbou556]

Thank you so much, sir. This is super helpful for fresh engineer like me.

[@bengthebrazilianengineerinAus]

thank you :)

[@lupocattivo8777]

Excellent presentation

[@bengthebrazilianengineerinAus]

Thanks :)

[@peterokitoi7757]

Hey thanks for the video, I would love it if you started a building series initiative, like RC buildings, Steel structures, Bridge series and so on and combined each video into a stage incorporating theory and its practical use. In all this thanks

[@amywalton2080]

Great explanation. Thanks

[@Pgan803]

Good Info. Learn a lot. Thanks

[@bengthebrazilianengineerinAus]

Thanks my friend

[@murtadhaabddulkareem7913]

Great Video. Conceptual. Practical. And easy to absorb the knowledge. I wonder if you can upload more videos frequently. It is highly appreciated if you upload conceptual analyze and design industrial structures (oil and gas) or buildings using Robot or Staad. If you have online courses, I would like to enroll.

[@bengthebrazilianengineerinAus]

Hi Morteza. Thanks for the support. Unfortunately Oil and gas structures are not my expertise, but I will start uploading more videos on larger structures soon.

[@SamEngTutorials]

Great explanations and demonstration

[@bengthebrazilianengineerinAus]

Thanks Sam :)

[@MrTb2arvd]

really good points! =) great video

[@bengthebrazilianengineerinAus]

thanks :)

[@mustaphaadebayo3674]

Great video This was really helpful ❤

[@bengthebrazilianengineerinAus]

Thanks Mustapha ☺️

[@bryanpatino7513]

Great explanations!

[@ailenei88]

Great video.Thank you!

[@momenabukhairan690]

Great video, thanks for the info and nice hair cut

[@bengthebrazilianengineerinAus]

hahaha thanks for the compliment. I'm enjoying my hair while I still have it.

[@momenabukhairan690]

I lost it completely otherwise i wouldn’t notice yours 🤣 Im enjoying your videos continue please

[@bengthebrazilianengineerinAus]

@@momenabukhairan690 hahahah :D the receding hairline always win eventually . Thanks for the support

[@MiguelPMoya]

Awesome information! keep the videos coming please!

[@bengthebrazilianengineerinAus]

Thanks Miguel :)

[@user-yw2xx8jv3o]

Good explainationn. Thank you.

[@senthilvadivelnithisan6247]

Excellent , now I got clear idea about connection😁

[@bengthebrazilianengineerinAus]

Awesome. Thanks

[@rooben_]

Great video!, thank you again!

[@bengthebrazilianengineerinAus]

Thank you for watching my friend

[@AbuKassimMohdSaleh]

Very good lesson, just to confirm with you sir, that mean i can weld the i beam the column directly but with stifferner plate

[@bengthebrazilianengineerinAus]

Thanks Abu. You can weld a beam to a column , but bolts are usually the preferred method.

[@ChinTanLimbani]

Nice explanation

[@bengthebrazilianengineerinAus]

Thanks ChinTan

[@zambotwu]

So good. Subscribed.

[@bengthebrazilianengineerinAus]

thanks mate :)

[@filmonokbu3360]

Hi! Thank you for this practical video. I have some questions regarding: 1. Connection between CLT floor panels 2. Connection between CLT floor and Steel beam 3. Between concrete precast Hollow core floors 4. Between Hollow core and steel beam. How do you thick we can model them in a software? Many thanks!

[@bengthebrazilianengineerinAus]

hey..I haven't designed many CLT buildings so you may be better off asking someone with experience on that.

[@SurinderKumar-re1ul]

great video, my friend

[@bengthebrazilianengineerinAus]

thanks my friend

[@deyuhao8538]

Well explained.

[@bengthebrazilianengineerinAus]

Thanks Deyu :)

[@timothypolo7062]

Another great video. Keep up the good work.

[@bengthebrazilianengineerinAus]

Thanks Timothy

[@ghilmandilshad9495]

Such a nice video wish can get in touch with you !

[@ToluwaniSamuel-v8o]

4:39 what about the end span-end joint, are they meant to be assumed as fixed or pinned, because I see in some methods of analysis e.g. Moment distribution method, they some times assume the joints at the ends of the end span of a continuous beam as pinned resulting in total moment at the far end support being zero. I thought its because the moments would be small; so negligible, but in some cases recalculating it (assuming the far end support as fixed as opposed to b4) there could actually be a significant amount of moment. So why do we then neglect that moment and assume the far end support to be pinned when in real life its actually fixed I.e there is moment at the support I'm referring to an RCC Beam btw🙂🙂

[@bengthebrazilianengineerinAus]

send me an email with an image of what you're triyng to solve. I think it will be easier.

[@olorungbemisolatitus7566]

I would love to learn your Steel structure design(s) videos on Robot Structural Analysis. This is quite good!

[@bengthebrazilianengineerinAus]

Stay tuned!

[@leonardpeposhi5154]

Great video

[@bengthebrazilianengineerinAus]

Thanks :)

[@busolaatekoja9830]

This was really heloful. Thank you so much. Please is it possible to do an interactive session focused on reinforced beam-column rigid connection

[@bengthebrazilianengineerinAus]

Thanks :) what do you want to know about RC beam column connection? Just detailing?

[@busolaatekoja9830]

@@bengthebrazilianengineerinAus Yes please, the detailing

[@sothattheng8624]

Thanks for sharing!

[@bengthebrazilianengineerinAus]

Thanks for watching

[@alfonsoperez8535]

You just won another subscriber! I do have a question what would you consider the threshold for a portal frame to require moment connections instead of just shear connection? When is a moment to big for the connections to require them to be moment connections and where in the code is that info? Thabks

[@bengthebrazilianengineerinAus]

Hi Afonso, a portal frame is a lateral stability system. You cannot achieve lateral stability with only a shear connection. You will use shear connection in braced frames.

[@kgosirantshilo2836]

Just a question, if you consider moments are due to the rotation of the flanges a very stiff beam would not transfer moments because it barely rotates / deflects. I'm curious if the sharing of moments in columns and beams due to relative stiffness is also due to the level each member resists deflection, I.e whichever 1 resists deflecting the most hogs the moment. Please Let me know if I'm completely misinterpreting this

[@gregsharpe8453]

Great video!

[@bengthebrazilianengineerinAus]

Thanks Greg

[@lahiruwijesinghe6549]

Great video, thanks for doing this. Would you able to do a video on a simple base plate design for a steel column please?

[@ineyedaniel4954]

Great video. Can you please explain the whole concept of a base plate being fixed ie rigid and when it deforms due to inadequate thickness makes it pinned

[@alpeshmeghani8855]

Great Video, what is the ideal ratio of stiffness of; column stifness to Beam stiffness, in a Reinfoced Concrete frame?😊

[@bengthebrazilianengineerinAus]

Good question. Not sure about the ideal ratio. Most reinforced concrete structures are detailed to transfer bending moment so I would design it for full stiffness regardless.

[@joshuakelshall3516]

Have you done elastic analysis of a portal frame with an overhead gantry crane?

[@johndaveleones69420]

Can u make a video about fixed beams using square tub vs I- beams, and test which is stronger when they have vertical loads

[@eduardomonteiro2434]

Mais de ligações metálicas, pfvo!! Por exemplo, considerando a rigidez da ligação (pelo método das componentes ou outro que se use na Austrália) no Robot e vendo as diferenças de esforços. 👏🙌

[@bengthebrazilianengineerinAus]

Execelente ideia Eduardo. Obrigado

[@Y.S_The_3rd]

You are the bomb 🔥

[@wasifakhtar5895]

Thankyou for the detailed insight. Can you please elaborate more on when it is ideal to have a shear connection vs moment connection in base plates? Furthermore, for beam to column connections in the case of square hollow sections or circular hollow sections where there is absence of a web/flange, how the shear and moment connection are formed for them?

[@bengthebrazilianengineerinAus]

Hi Wasif, it varies from project to project. Typically you choose a moment connection if you need a rigid structure and due to architectural reasons, for example, you cannot brace the structure. Bear in mind that moment connections are more difficult to design, fabricate and build, not to mention the costs. There are many ways to connect tubular sections. look up guides by CIDECT online

[@wasifakhtar5895]

@@bengthebrazilianengineerinAus Thankyou for your reply. Keep sharing your content, it is quite informative :)

[@Loksta112]

Awesome, thank you again! Ok so question, Fixed vs Simply supported is due to limiting of rotation. What about a Steel beam in a Roof with Purlins above it BUT a Fly Brace has been introduced between the Purlins and the Bottom flange to stop rotation of the Bottom Flange. Is this now a Fixed Connection?

[@edp6364]

good stuff thanks

[@bengthebrazilianengineerinAus]

Thanks Ed P

[@shamamba02]

Good day sir, I want to ask when can these connections be applied in a structure? How do you know that the connection need to be shear connection or moment connection. ?

[@bengthebrazilianengineerinAus]

If I had to summarize this answer in a couple sentences, I'd say, we use moment connection for lateral stability or to reduce deflections, otherwise most of the time shear connections.

[@shamamba02]

@@bengthebrazilianengineerinAus Thank you sir!

[@bengthebrazilianengineerinAus]

@@shamamba02 no problems :)

[@iansk8forlife]

Hi Ed We gonna pre-anchor steel plate in concrete columns to connect steel I beams , is the bolted connection stiffer or welded one ??? I want to weld on L plates for shear connection and for moment as well all both sides it’s gonna be 4 . Or we can just weld it on . What is better ??

[@bengthebrazilianengineerinAus]

are you referring to the base plate connection or connection from the beam to the column?

[@iansk8forlife]

@@bengthebrazilianengineerinAus base plate

[@chappyaugusto]

I SAW YOUR LECTURED BENDING MOMENT BE AND COLUMNS STEEL MADE . COULD YOU TEACH HOW DESIGN STE CONEXIONS IN A PROPER WAYS !

[@cheekhai5554]

Nice

[@bengthebrazilianengineerinAus]

Thanks :)

[@ahmedyaqub2377]

How can I prevent cracks in partition walls due to deflected structural beams' interaction?

[@bengthebrazilianengineerinAus]

You have to limit the deflection. Masonry walls for example I use span/500

[@ahmedyaqub2377]

@@bengthebrazilianengineerinAus Sorry I forget to mention that the partition is non loading type

[@obedtari8390]

Genius

[@aliqadri4672]

Is the (stronger column and weaker beam) system is good for rcc construction or (stronger beam and weaker column) system..??

[@bengthebrazilianengineerinAus]

It depends on the spans. If the span of the beam is longer than column height, increase beam stiffness. If column height is higher than beam span, increase column stiffness

[@aliqadri4672]

@@bengthebrazilianengineerinAus so sir how do we stiff the beam ..??? and sir i think if span of the beam is longer then column then we stiff the beam but the columns remain much stronger then beam because of safety..???? And sir as the rule says all the rcc member who take load of any rcc member should stronger then that to resist it..???

[@bengthebrazilianengineerinAus]

@@aliqadri4672 When I say increase stiffness I mean increase the size of the element. You are correct, but a beam is subject to different internal forces (bending and shear) than a column (mainly compression). As long as you design them to take any loading they will be subjected to, you will be fine.

[@sothattheng8624]

If you can do the VDO about steel warehouse analysis with Autodesk Robot program to design fix & pinned connection for members & Baseplate is good.

[@bengthebrazilianengineerinAus]

Definitely planning to do a couple.

[@ahsanfilibuster]

Need information on foundation

[@axatrathod]

👌🏼👌🏼👌🏼

[@bengthebrazilianengineerinAus]

Thanks :)

[@wasifakhtar5895]

Also, as a practicing structural engineer, how do you personally design connections in a large scale structure? What is your go to method. Do you rely on any designated software for this task or an excel spreadsheet?

[@bengthebrazilianengineerinAus]

A combination of software, spreadsheets, hand calcs and standards.

[@obedtari8390]

Sie upload microstran steel design and concrete design Story building please

[@mbiat1234]

is haunching seen as a moment connection

[@bengthebrazilianengineerinAus]

Haunch is just a larger section of the beam. It helps with more space to facilitate the moment connection, but it's not a pre requisite for a moment connection. You use hanch to increase section capacity where bending moment is larger

[@exzar9684]

7:14 that kind of moment reaction is not possible in real life?

[@bengthebrazilianengineerinAus]

A perfect moment connection or pinned connection doesn't not exist. We design them as such to simplify the calculation. Some moment connections can be very close to be perfectly rigid, In the same way some shear connections can have some rigidity and transfer moment, however its so small that we usually neglect it. There are semi-rigid connections as well if you want to go more in-depth into connection design.

[@exzar9684]

@@bengthebrazilianengineerinAus hello, thanks for the reply. I meant to say those kind of moment reaction values as shown in the video at the timestamp sorry 😆.

[@valecturas]

Could you record this in portuguese please

[@op-vw8sd]

Misleading. Whether u have stiffeners in the column or not the beam will rotate (together with column) anyway. U are comparing a rigid connection to a fixed end (it is an end not a connection), which is of course different but there is nothing wrong calling the first pic a rigid connection. A rigid connection is based on the assumption that beam-column will maintain 90 degree when they rotate and stiffeners or not will not change that. And the flanges don’t take the moment. The flanges take the compression/tension. Moment is taken by the whole section.

[@bengthebrazilianengineerinAus]

Hi mate. Thanks for your comment. Appreciate your input. The point I'm trying to get across here is that rigid connections are not all that rigid in reality. Connection rigidity is often overlooked in my opinion and could lead to serious issues in design. If you connect a 460 I beam to a toothpick, it doesn't matter if the connection is rigid or not. The toothpick is so weak compared to the I beam, that the connection you have assumed "rigid" will be a hinge. Regarding the "flanges take moment": the top fibers or bottom fibers or flanges of a beam play a much larger role in resisting the flexural forces (as you said) from bending.

[@op-vw8sd]

@@bengthebrazilianengineerinAus But rigid connection is rigid connection. You can’t compare the rigid connection to fixed end and call the rigid connection “not so rigid”. The later one is not a connection but a restraint. A rigid connection is based on 90 degree assumption. If you decrease your column stiffness and thus getting a smaller moment at the connection that doesn’t make your rigid connection “not so rigid” or even a hinge. The moment is reduced because the column is softer and rotate more instead of the connection. As long as 90 degree assumption is valid it is a rigid connection. Again, you cannot compare a connection to a restraint and call the connection not so rigid. That’s totally two different things.

[@remonbasheer3122]

A rigid connection is a joint that assumes the angle between the members is kept constant (doesn’t have to be 90deg since members aren’t always connected at 90deg). This assumption relies on the relative stiffness of the supporting member. If a relatively flexible supporting member is connected to a supported member then this assumption won’t be valid anymore and the angle will change due to large stresses and deformations hence will be less rigid or will start to act as a ‘spring’ support with relative rigidity. Hence a rigid member is only an idealisation and should rather be thought of as a spring with relative rigidity regardless of what connection you use. @op is referring to the rigidity of the actual steel connection and how much deformation they can take. A rigid connection usually refers to the relative stiffness of the members and how good they are at transferring moments where as a steel connection that is rigid doesn’t always provide a rigid connection between members (transfer of member moment is not equal at joint) because a rigid connection depends on the relative stiffness of the members as well. This is what we usually mean when we refer to rigid connections and not the actual rigidity of the steel connection being used.

[@BrandoDennis]

This video is not going on to long! Please keep talking! Please!

[@bengthebrazilianengineerinAus]

Thanks Brandon. Glad you enjoyed it :)

[@mosarila8927]

Ur shirt is exploding 😅why wear so tight

[@bengthebrazilianengineerinAus]

hahahaha I had put some weight on back then. Shirt fits fine today

[@philweed1603]

Your shirt is too tight, my friend.

[@bengthebrazilianengineerinAus]

😂 You're not the first person who said that haha I had put some weight on back then

[@william0mccarthy]

Great video, thank you!

[@OkeamuteIdolorUnscripted]

Great video!

[@bengthebrazilianengineerinAus]

Thanks :)