Stiffness due to geometry! That short sentence changed everything!

@Eagle_1174

2 жыл бұрын

Stiffness due to geometry = Moment of inertia Stiffness due to material property = Youngs modulus of Elasticity.

@Rayquesto

2 жыл бұрын

@@Eagle_1174 Right. When you derive the sectional forces, the effective stiffness in terms of how the strain of the section changes with stress will come down to something involving x^2 with area. So, that turns out to be equivalent to the second moment of inertia as it is defined. The elastic modulus is also included in the bending stiffness. So, although those are true statements, the true stiffness of the beam is a combo of both in a sense. Only stating this to allow people to understand that for bending you need both for the full stiffness.

finally i found a video that talks about what it is....a lot of people teach how to calculate it but not what physical meaning of it.....thank you a lot

@purdueMET

7 жыл бұрын

You're most welcome :-)

@Hambin0

5 жыл бұрын

The is the first location I’ve ever seen explain in practical terms. This guy is awesome

@_schnelli4800

4 жыл бұрын

@@purdueMET thanks I needed a practical example of this.

That’s the best example of demonstrating the moment of inertia! Helped me a lot in understanding. Loved the fact that you showed the difference in calculation and real life.

Finally in the last year of my civil engineering degree, I got the concept.... Thank you sir..

Hi sir.....! Am from Sri Lanka & thank you very much for your service for an engineering student like me. your explanations are really simple instead of being too complicated. I keep watching you and learning from you instead of attending lectures.

Great demonstration. And the way you explain theory is very detailed and easy to understand. Keep doing the good work!!!

I really really wish that you would continue making videos...Everyone can understand the theory, but the practical demonstration makes sure everyone understands and remembers WHEN and HOW to make use of it!

been looking for this everywhere, excellent explanation. THANKK YOUUU

This is the only video that made me understand the concept...Subscribed....Hope to learn more!!!!!!!

I was looking for such a brief explanation...that's too good explanation .

This really helped solidify my understanding! Thanks a ton!

Finally!!! A video which explains Inertia in SOM

Absolutely Ur Explanation And Physical Meaning got me really feel it..Thanku

Oh my god, these videos are amazing!

Perfect explanation.

hello professor. Thanx for this amazing video, please keep making such videos in the near future.

It's really good... after watching lot's of video finally I got concept...

Great visual video, thank you!

@purdueMET

2 жыл бұрын

I'm glad you like the video :-)

Superb ! Like due to practical implementation shown here.

Perfect explanation!

after 4 years of mechanical engineering , finally i understood the concept of ( capital i in beam equation ) thank you so much , you don't know how much difference that made in my life . please keep sharing you superior knowledge.

@carultch

2 жыл бұрын

It's a capital I, and the shape that has the best value of capital I, looks like the letter I. Makes it very easy to remember. Too bad the comments don't have a serif font where you can see it better.

Possibly the best explanation on Area Moment of Inertia!...😍😍😍 Walking on that beam was a bit scary! 😂😂😂

@purdueMET

7 жыл бұрын

That's why I mounted it so close to the ground :-)

u r my favorite professor

@purdueMET

2 жыл бұрын

How nice, thank you :-)

Greetings, It was really great way of explaining. Found it useful

Greetings from South Africa. Thank you for the brilliant explanations. I can tell that you have great passion for what you do.

@purdueMET

7 жыл бұрын

Thanks very much. It's a real treat to be able to reach students around the world. Hearing from a viewer in South Africa is just great :-)

@VantomChannel

7 жыл бұрын

North Africa (Egypt) as well

Thanks for making the video.

Great explanation!!

Best teacher....

Thank you so much sir!

Good Explanation!

I wish he was my prof. in college. Also as soon as I saw him writing with the left hand I knew he is smart.

Good explanation❤

Great video..thanks

Thank you for this professor. I do have to comment that there are times you MUST absolutely fight tradition. If people didn't fight tradition, slavery and women not allowed to vote may still have continued. As such, not calling them "two by fours" is just one step in the correct direction. Metric system is where it's at.

Very helpful video ❤❤

great educator

Amazing sir

This was a great video!

@purdueMET

2 жыл бұрын

Thanks :-)

thank you sir that practical xplaination 🙏

thank you ❤

Thank you so much. It was so usefull.

Thanks man, god bless

very helpfull thank you very much sir

Wow. That was a revelation for me. Thank you for sharing that with us.

@purdueMET

2 жыл бұрын

You're most welcome. I'm glad the video was helpful :-)

Thank you sir

Thank you sir.

I was wondering if that 2*4 breaks during the video. Haha, Proud to be a Boilermaker.!!

nice thanks so much sir

@purdueMET

2 жыл бұрын

You're most welcome :-)

lovely

from iraq btw. great explanation!

@purdueMET

7 жыл бұрын

Thanks very much :-)

excellent video on the subject, principles and real-life demo. It would have been interesting to make the same beam with 1/4-inch-thick pine box beam glue up, same size as the pine board you are using and demo that also. I am sure the beam would hold you also. I would have been good to have measured the deflection and know your weight to have further understanding till you have broken the board. The video could of had a free body diagram, to define the 'design specification', review of the formulas, did the demos, talk a little fo tbe design requirements and safety margins would of completed the video for me! But well done, nevertheless.

Sir can you make a video to explain radius of gyration also. Thank you

most lecturers teach this topics on materials in civil engineering class,but they never give us the practical meaning of them.i graduated from civil engineering class in kenya but struggled to understand the practical aspect of things like moment of inertia till i started researching on youtube videos.

Hello, Professor! You call I "stiffness". How do you call then EI? Thank you for the answer and the videos!

@purdueMET

8 жыл бұрын

Hi Marius, EI is a stiffness expression that includes both material contribution and the contribution from the cross-sectional shape. I is the portion of the stiffness due to geometry - the cross-sectional shape.

@kingz.a1918

5 жыл бұрын

@@purdueMET Superior answer!

When you said 48EI in the denominator of that expression did you mean (48•10ᴵ); as in 48 by ten base to the degree of the moment of inertia?

@kunjanmushyaju3300

3 жыл бұрын

No

@kunjanmushyaju3300

3 жыл бұрын

E = young modulus of elasticity

@Bryan_Kay

3 жыл бұрын

@@kunjanmushyaju3300 why didn't he just use Y like a civilized person?

Eureka! 👍

stiffness is 5.444 times higher on vertical position, but strength is the same, am i right?

@purdueMET

2 жыл бұрын

I'm afraid not. The normal stress is My/I. If you substitute I=1/12*b*h^3, it works out that the stress at the top and bottom of the beam goes down as h^2

Sir,I understood everything clearly but I am having a small doubt why moment of Inertia is calculated only for cross sectional area??

@risky_world5692

4 жыл бұрын

I think that When the load is applied on the beam it acts perpendicular to the surface and try to bend the material along its surface. And the material shows stiffness (resistance to rigidity) towards it, and to calculate how much stiffness the beam or material shows we calculate it's moment of inertia. For the calculation of moment of inertia we need to know the cross-section of the element along a desired axis we want to find. Remember when we study in class 11, the moment of inertia with its parallel axis theorem. In there the cross-section can be of regular or any irregular shape. But in case if beams we have standard shapes. I hope that your doubt is cleared. Furthermore you can calculate the beam stiffness at any point of fibre by changing its axis. Any more questions..... reply me.! Keep learning and growing.! *The knowledge is aggregation of marginal gains*

@saikumarnandipati9223

4 жыл бұрын

@@risky_world5692 thanks a lot

i=1/12bh^3......Where did the 1/12 come from, and why is h^3....?

@carultch

2 жыл бұрын

It comes from the cascading coefficients of 3 and 4 as you take integrals of a polynomial function.

Shroud

We are poor, no one has told us such things in the University.

Hi sir, greetings from a student in India! Your videos are brilliant and really really helpful, thank you so much! This channel deserves to be a lot more popular 😊

@purdueMET

8 жыл бұрын

Hi Stephen, I think so too ;-) Thanks very much for your encouragement.

thank you sir

Soooo clear. I love your explanation, my professor couldn't explained to me that simple concept. Muchas gracias.

Crystal clear explanation with practical examples

This really made me soooooo happy. Thank you so much for this Sir!

Your lectures are awesome before this area moment of inertia was such a difficult concept for me thanks a lot

Thank you professor for showing us in the actual model👍🏽👍🏽

Thank you! I'm a visual learner so that demonstration at the end really helped

Thank you for making this so easy to learn!

Superior explaination !

i was wondering why h^3 then experiment explained everything. thank you very much.

Amazing vids!! Greetings from Chile!!

Thank you sir It's best explanation about Area moment of inertial

what I found! This video is so great!!! Thank you very much

First time i got my head wrapped around "area" moment of inertia ! Finally able to visualize the difference it makes !

Thank you! Just what I needed

This was so helpful! Thanks for the video :)

That really was smart teaching........I was stuck on this doubt of mine for quite some time now that why do we consider MOI for calc. of deflection in beam but you jst cleared this in 7 mins.....awesome

Thank you sir, I can understand easily by this video

Very good explanation sir.

Thanks for the great explanation!

@purdueMET

7 жыл бұрын

You're most welcome. I'm glad the video was helpful.

Great video! thanks!

thanku and best part is knowing that moi is the stiffness of a bar due to its shape

finally I understood what is moment of inertia

Thanks you so much sir it is vary help full to me

Sir, Thank you

Thank you Sir. Please solve problem on second area moment of inertia for pendulum wrt axis.

Thanks sir

Why in the case of twisting moment polar moment of inertia is consider ?

Can someone please explain how the squared distance from the centroid relates to the equation (which you have to multiply with the area to get the area moment of inertia)?

thanks sir

I understood that means stiffness. Can you relate the moment of inertia with the bending moment of equation i.e. M/I=σ/y with a suitable physical example ? Thanks in advance

@Rayquesto

2 жыл бұрын

It’s everywhere. Think of it as the stress at any point perpendicular to the axis of bending is no different than a thin fiber in tension or compression; at that point, the strain is the stress divided by elastic modulus. The strain in beam can ALWAYS be derived from the linear elastic and fully planar assumption where the section MUST rotate about some point (also known as the neutral axis) and maintain a linear profile. This rotation is proportional to a curvature radius and length of the beam with small changes along the radius (called curvature). It is then possible to relate the length and the dimensions of that section to the strain which then becomes integrated with definitions of E and I. Let me know if you would like me to show the entire derivation.

i love his tee

@purdueMET

7 жыл бұрын

Thanks, though it may somewhat overstate my musical skills...

Well done. except you need to mention the role of buckling.

Sir, when we say first moment of area = O, what do we mean by that , physically?...like area moment of inertia tell stiffness due to shape.

@carultch

2 жыл бұрын

Moment in general means quantity multiplied by distance to a reference point. First moment of area is area multiplied (or rather integrated) with distance to the centroidal axis. Second moment of area, squares this distance. A practical reason why we care about first moment of area, is the strength of a member against shear loads. Maximum shear stress is inversely proportional to the first moment of area, and thus the shear strength of a cross section, is based on the first moment of area. The first moment of area is also part of the algorithm for calculating the centroid.

👌