Area Moment of Intertia of an I Beam.MP4

Here's how to calculate the area moment of inertia of an I beam using two different methods. They are equivalent, so you can use either one.

[@Devineeno1]

Superb explaination/teaching. If our lecturers were this good our course would take 1/3rd the time! This is possibly the greatest possitive the internet has ever brought to the world. The gift of free knowledge to anyone who's willing to take the time to learn.

[@acoti]

I really appreciate this video. You are clear, concise and don't make any assumptions about what we already know when explaining this. Thank you.

[@purdueMET]

It's great to know that people are learning from this video. You are most welcome.

[@bbfcbvftjn5089]

Till today mr , 13 years later

[@purdueMET]

Super. You are most welcome. It is one of the little joys of my life to get messages like your and to know that these videos are helping.

[@Tigeress8482]

Needless to say, that was great and very helpful, thanks! Way better than trying to decode the practical meaning of Wiki formulas.

[@PSPx5000]

Great explanation! You're better than my university professors

[@klowranc]

You're awesome! I'm a mechie calculating the necessary structural support to handle the cyclic loading of a mounted .50 cal machine gun on a helicopter. So you students may just have to use this one day! Thanks for the refresh Professor!

[@AbuOmar1970h]

Again and again, want to say thanks to the people who work at youtube . And people helpers who help educational videos like these . Thank you my brother . helpful

[@eunicemobula4584]

9 years later and this video is sitll crazy helpful! Thank you sir!!!

[@purdueMET]

Thanks very much. I'm really pleased to hear that the videos are helping you.

[@AMadWalnut]

I like the badass way he turns from the board at the beginning. Like we're distracting him from contemplating Stuff, but he doesn't care because he's so badass.

[@mettecharlottejensen6947]

Eminent..;)) You have the super skill of making it seem so easy... By simply translating the professional terms into words we already know...;)) THANKS...!!!

[@purdueMET]

Wow, thanks. I'm glad the videos are of help to you :-)

[@mettecharlottejensen6947]

..;)) So now I dare asking you...; have you made any videos on 'relative efficiency of various Beam Shapes', 'deflections on beams', 'Shear Formula' and 'beams with axial loads'. I'm studying for my exam in Mechanics (Litt.: 'Mechanics of Materials'), and it happens to be that out teacher is unable to 'really teach'... Your videos are helping me a lot..;)) THANKS...!!!

[@Xaldinwinddude]

Thank you again! i've watched multiple videos of yours and you've helped to explain alot. Someone was doing negative area method and I had no idea what they were doing until I watched this

[@razerspurs]

really useful, much easier to understand than the wikipedia page on this subject, or anything else i've found for that matter!

[@purdueMET]

You're most welcome. If you like these videos, please help spread the word. Counting hits on my KZbin channel seems to be one of my hobbies :-)

[@patricksoderborg7933]

Clarity at it's best! Thanks!

[@TheBetterRyanKelly]

These videos are amazing, I go to Binghamton University and it's difficult sometimes to understand my professors, you articulate each and every part of an equation in plain English and make me feel dumb for not understanding it the first time around! (I mean that in the nicest way possible) Thank you.

[@alexthehunt1994]

Thank you, I can't even begin to explain how helpful this was!

[@joseortega9712]

I LOVE YOU MAN.... YOU SAVED ME LOTS OF TIME... NOW MAKES SENSE!!! THANK YOU

[@HamsayT]

Brilliant video - finally i can make sense of my lecturers notes!

[@miad1212]

I wished we had a teacher like u here!

[@dizrob]

This is such a great video! Please keep them up! You're helping a lot of people

[@mikemai8568]

It's a great video. Thank you for all your hard work to filmed and posted this video.

[@Ipally2601I]

You have helped me so much! Keep these videos coming please!!!!

[@purdueMET]

Sorry for the late response. This is indeed the parallel axis theorem. It works for mass moment of inertia as well.

[@mersadz3743]

Beautiful, very good job. Thanks.

[@amandastark10]

Thank you so much! I might not fail my statics final because of you! =]

[@MultiValentino2011]

THANK YOU SIR! MABUHAY KA! (LONG LIVE)

[@torthetori]

excellent job, very clear explanation.

[@samniasary]

Thanks man I saw that video a couple of weeks ago. Thank you mate.

[@finnersz]

just what i needed for my mechanics exam tomorrow

[@RubyFOB]

THANK YOU. Totally forgot what the formula was.

[@Atlethehun]

Great thanks for taking the time to make this video - very helpful!

[@kakbar10]

thanks alot your videos are so helpful

[@navarchitect1]

Thank you very much sir ..that was very helpful

[@MixTheMeister]

Your videos are amazing! Thank you so much!

[@marjopy13]

Very useful.. you should be teaching at uni!!!! Thanks a lot for your help... =)

[@Moatazbahr]

you're a legend!! thanks for the very informative video

[@kaps1308]

very good explanation sir thanks you very much

[@seanfogarty211]

Excellent explanation. Thanks a lot!

[@purdueMET]

You're most welcome. If you like the videos, please spread the word. I'm trying to keep my boss happy :-)

[@cerialkillar]

(110-40)/2 = 35 The whole lenght - the lenght of the beam and then devide by 2 because there are two sides

[@OlimpiuVictor]

Hello dr. French ! My name is Victor and i'm studying Civil Engineering in Romania. Your videos are amazing . i was wondering if you could explain the Jurawsky and Navier deduction formula. I never understood from my teachers. I will appreciate it ! Please keep upload this good work because your videos are very helpful! Thank you , Victor

[@juZby]

@juZby never mind! I managed to figure it out. Thanks again!

[@arwaabougharib8698]

I've always wondered what the physical meaning of the moment of area is..

[@abbasajorloo9455]

Thanks a lot for this video. this was very helpful.

[@samniasary]

dude you see the gap in the middle? It's 40mm. So 40+35+35=110. He explained it at the beginning of his video. I think it's around 00:25

[@NXTMusicianBassist]

No. This case was special because we knew I1 and I3 were equal. In the case you mentioned you would have to figure it out separately.

[@3rbdh]

you have taken the hard way to that easy problem, i'm skeptical if u were reading while doing this. anyway

[@juZby]

thanks a lot for your videos, just one question: what would the distance 'd' be if the individual shapes of the centroid weren't aligned? i.e. it was more of an s shape? simply use pythagoras to find the diagonal distance? thank you

[@A-R53]

May Allah bless you sir 🌼🌺🌸🌺🌼🌺🌸🌺🌼

[@anupam25091987]

sir , thank you so much for the lecture, it helped me a lot . Can you please upload (or do you have ) a video explaining the moment of area of thin walled sections ?

[@TheSpyker123]

hi im from south Africa great class you really helped me allot. can i just please ask you a favor is there maybe a way that you can rename your clips according to chapters or nr the clips according to topics cause im battling to figure out where the videos start . once again thanks so much really helpfull

[@villy8778]

Thank you so much. Where were you in my first year?

[@evo1empire]

Why did my lecturer not teach me like this at uni? life is suddenly so much easier and clearer lol

[@ajcraig99]

you need to draw a bending moment diagram. i believe he has made a video addressing this.

[@dayxwalker]

Thanks nice and clear . Only bit I am not sure on is you did not seem to use A in the first method ? You only added I (Inertia) and missed A (Area). I know that d=0 as the centriods are the same just not sure what happended to the A. But thanks anyway will just use the second method

[@imstudentxxxxx]

very good video! thanks!!

[@stevenhamer5826]

how did you work the base out to be 35mm ? should of really shown that part

[@tallkekepink95]

Did you ever find out how? I am still lost.

[@tallkekepink95]

I just found out how from a comment I read below! Its 110-40 / 2

[@madman1452]

great vid. keep it up!

[@Things4Free-Things4Free]

Thanks a lot,Sir!

[@hanoosh1100]

Hello can you do a video on working out the centroid and second moment of area for a 'C' shape . Thanks a lot

[@sebastianbidoli9693]

You are my saviour

[@mrhumz]

Excellent!!!!

[@nakas12ify]

Thank you so much!!

[@Kurohamiy]

Thank you so much ! This helped a lot

[@bhaskarrasaily1433]

What about calculating moi along y-axis using 1st method??? Seems like it doesn't work.

[@Vathanaization]

Thank you very much.

[@sherazkhan2721]

great work...thank u sir

[@Stephenishere]

thank you for this video! :)

[@WGPJayasinghe]

Thank you so much for this help..!

[@shaf1ke]

hey guys im a bit confused here, this is second moment of area about the neutral axis(centroid) right? say there was a X-X axis at the bottom of the I-shape, to find the second moment of area about the X-X axis, do you use parallel axis theorem? thanks

[@MrMarvelCraft]

3:44 "about the x-axis since those have the same altitude d is 0 for all 3" they have the same altitude on the Y AXIS not the X AXIS so have you just been fortunate and your mistakes cancelled out anyway or are you working out inertia about y instead?

[@AtelierFleur]

Thank you!

[@brandonelliott633]

Great.... but now how do you calculate the area moment of inertia about the Y-axis?

[@aliourangiasr8066]

Thank you very much sir

[@REMOV28]

thanks, super helpful

[@shazrinyusof8550]

thank you sir for your explanation. but, i have a question sir. when i calculate my moment of inertia, i use the subtraction method where my I= 1/3 bd^3 . is this method applicable for all types of questions?

[@nasteve61805]

Thanks, good insite.

[@samniasary]

What if we have to get the maximum bending stress?

[@yongwu1226]

how to calculate the second moment area about minor axis

[@jkf1192]

what if the lower section of the beam is wider, is I1 still going to be equal to I3 ?

[@nguyentuan1990]

how did you figure out that the base of each smaller retangular is 35mm? I couldnt figure it oiut.

[@japedemino5850]

whats the difference between second moment of inertia for bending moments (I) and polar moment of inertia for Torque (J)?

[@ahsonreza4553]

jape demino polar moment is moment of inertia around x axis + moment of inertia around y axis i.e.: Ix+Iy , hope that helped.

[@prashantmali02]

hello sir i have read somewhere that for same area the "stepped i section" has more strength than that of simple " i section " is it true...?

[@i_am_soumya_-_3748]

sir can u plx show us how to calculate the moment of inertia of an irregular shaped cast iron beam

[@durgacreation9232]

thank you sir

[@ksdnsdkumar1375]

@5:57 how base is 35? please somebody explain.

[@guzars123]

thanks a lot .

[@TheCSSoup]

where did the 35 come from? 110/3 = 36.6 ? not 35?

[@MarryMeSyn]

Is this the parallel axis theorem?

[@MSavagePill]

How did he get 35mm? can someone please explain. Thanks.

[@GBizzleism]

@jon4156 To be fair he has limited board space and you could just not be ridiculously lazy and re-wind the video to see the dimensions at the beginning.

[@SaraSara-qj7xo]

هل حل I beam ﻹيجاد moment of inertia ف محور y يختلف عنه ف محورX

[@francisvalenti2541]

There is no way possible from the dimensions you have written on the board to find a web of 35.

[@jon4156]

No disrespect intended, but I find this instructor confusing. For example, he erased the dimensions for length of the I-beam in boxes 1 and 2, then drew the dimensions for the centroid distances which happen to be the exact same number (110mm). He next calculates "I" which uses "b" (110mm), but the diagram on the board shows 110mm as "d". Please make sure your diagram shows the numbers FOR THE EQUATION you are calculating.

[@divyak601]

sri the beam is symmetric the location of centroid is centre that i mean the value is d=130 , not 110 mm

[@N62MajorBlast]

110mm is the distance of the centroid of both the top and the bottom rectangle from the centroid of the entire shape. it is NOT the distance from the edges of the top and bottom rectangles. the missing 40mm is the sum of the distance of the centroids of the top and bottom rectangles from their edges. The only number we need to take note of is the distances of the centroids.

[@tallkekepink95]

I was confused on that part too. So basically he just did 260 - 40 / 2 which gives you 110 right?

[@noahkaiba]

Why is the Purdue MET department so much better at teaching than the Purdue ME? I learned this through Purdue ME teachers, and they suck!

[@karansharma-mb7rb]

In -ive method you used formula for box 2 and 3 i.e i2=i3.. 1/12bh3= 1/12 X 35 X(180)3 how 35 came??? :(

[@tallkekepink95]

I think the 35 came from 110-40 / 2

[@jakehunt204]

Can someone please put a filled out equation for the last bit?? All i get is 1.173 x 10^10

[@tallkekepink95]

(5.867*10^5+(110)^2(4400))+(1.944*10^7+(0)^2(7200+((5.867*10^5+(110)^2(4400)) = 1.271*10^8 :) Hope I helped! xD

[@chocoreyniel3657]

how do you get the 35mm?????

[@radancheng3374]

I think he is assuming all the bars have different length but same width 40mm,then (110-40)/2=35mm

[@tallkekepink95]

Thank you I had the same question!