Method of Sections for Truss Analysis Example - Statics and Structural Analysis 

I'm a former engineer returning to the field, studying for the FE/EIT exam. I'm re-learning everything. This is super helpful! Thanks!

It may be the fact that I've taken so many structures classes but it's amazing how simply you put that. In my Statics course I never understood how to do this but it just clicked! Great job.

Over a decade later these vids are still helpful

Thank you for your AWESOME videos. They are thorough but quick! You dont take forever to explain stuff but you go over important points systematically! AWESOME!

😭im so happy to find your videos. THANK YOU SO SO MUCH SIR.2022 ,10 years after your video but stil one of the most detailed explained video of static in youtube❤️ wish you bests. 6 June,2022 Civil eng dpt.Türkiye.hacettepe üniversity When I check comments of people here, they were like for 8,9 years ago. I was just thinking about all that people. How are they now?how was their exam back then? What are they doing? This circle of life is interesting. When you made this video I was about 10 and some people watched it,10 years later Im watching it.hahaha I cant imagine that little Aynil stepped on this way.fate... I think some people in future years may read my comment,want to say to you just stay strong in your way,if you get tired take a rest but dont give up. Look at your back,thousands of people walked in this way,you are one of them.you are not alone.its not the end of world dont worry keep calm. The stress of exam night believe me all of us exprienced that.keep calm. Wish you all bests.May Allah help us🌼

the line of action of the total FDE goes through point A, therefore it induces no moment about A.

For the summation of y, shouldn't it be FDEsin a?

Thank you! you didn't overdo it nor did you rush. understand trusses much better now. :)

Really like the way you've explained things here! It's hard not to sleep in class with my current statics professor.

THANK YOU. I've been struggling to learn this so much but your video made it so simple!

Hi, when you solve for FNE, why did you not include FDE in the sum of moments? Wouldn't the x and y components of FDE create a moment on A?

Wow! I think your are the best explaining this stuff. I have learned so much from watching your videos.

excellent, and clear! One of the more complex trusses I've seen on these videos, which is a good thing. (not many trusses have only 5 members) Thank you.

THANK YOU !!! I have to do this for my engineering class, and next week we have finals ! This helped me so much ! You made a couple mistakes, but I know what you meant. Thanks a lot man.

Just some algebraic errors but an excellent tutorial. This is the best I've seen so far and will definitely help in my exams.

Hi, when you are calculating the sum of forces in the Y direction, why do you not take account of the 10k forces acting down and the 35k reaction force? thanks

Apart from a few mistakes (which are mentioned), great video and explanation.

oh ! I' m really pleased because I am able to watch this video!!! Really appreciate! THANK U FOR YOUR HELP!

Great Video thoroughly enjoyed it! Maybe try zooming in more and you added a15' instead of 10' for that last calculation.

thanks man i was about to give up on applied math. you the real mvp

Watched method of joints, method of sections, analysis of frames and machines in prep for my exam later...helped a lot, thanks! :D

After making the sum of Horizontal and Vertical forces = 0 , you only need to make the sum of the moments around joint (A) = 0 in order to find all the three req'd member forces.

Great work, you have a great pace and thorough explanations.

Thanks for the question. Yes, you are right. I got sloppy at the end of the video with my algebra. I've considered taking the video down...but it seems to be helping more than harming thus far. You know, It's like owning an amazing house but a crappy bed...you may feel good but your back hurts after a while.

Helping engineers all around the world, structurefree

thanks a lot bro , you just made my structure analysis so easy .A BIG THANKS.

@TheImran826 yes. it should be sin.

again goooood job,i love it

@structurefree, I'm not sure if anyone has pointed this out but when you sum the moments about N to get FDE the third term should be 10k x 10'. You have written it as 10k x 15'. Funnily enough when you calculated the force you have corrected it without correcting it on the sheet. Not that I'm trying to be a stickler, just thought you'd like to know. Thank you for the video anyway. Very informative. It's been a while since I touched this stuff.

Wish you taught in our university!

woww thats really awesome explaining ... thank you and one thing i like about this video that you explain every little thing that we sometimes get stuck to continue solving the exercice... Anw thank u so much

You are a great teacher

No, I agree with you. Why throw out a great video over one tiny little thing? You could just put a message up at that time in the video letting people know I guess. All of your videos have been extremely helpful in MoM and statics. You always do a great job :-)

Wait! when taking moment about a why are you not taking into account the x and y components of Fde? aren't they also creating a moment about a? ....why am i expecting a reply... this video was made like 2 years ago.

i used the moment about E to calculate FNM.

Thank you so much for this informative video! it helped me understand the method of sections a whole lot better! :)

So many mistakes, but nevertheless this video is very useful for understanding. Thank you

i doubt if the sums of cut components add up to zero but thanks .its really helpful

thanks a lot for the free help, but when your taking the moments about the three points, how come you can ignore beams OD and PC?

you know what this is an great attempt..i appreciate it..keep it up..cheers

That was awesome thank you. I finally get it! Makes total sense!

Thank you~ it has been very helpful, and thanks for putting in the note to clear up the error.

I wonder if it's possible to use the equation you made in the summation of Fx and Fy to obtain the internal forces of the members FDE and FNE since you already have the internal force FNM? -By just obtaining the angles needed -and by using algebra(matrix) or by simply plugging in the values needed in the calculator? Is it possible?

wow! i made all kinds of mistakes. although, i didn't use the sum of forces in the Y equation, i should have included the loads. -10^6 points for me.

That was really helpful !!! Thanks a lot.YOU ARE AWESOME

Thank you so much! Helped clear up some confusion I had about a couple little things.

Great video!

Where you able just to start with moment at N to find the Fde, then moment about A?

Thank you for your great video

by finding the value of force NM we can put the value in first two equations(sum of x forces equation and sum of y forces equation).then we have got two equations with two variables and we can find the angle. then solve the both equations and we have got the values .no need to find moments at A

may I know for the vertical equation, why we do not need to count Ay, three 10k force inside?

Is it because it's symmetrical in force on both sides (not about the shape), that's why we can apply the 'cut through' method? Thank you.

these videos are really so helpful,thanks man :)

another helpful video

THANKYOU SOOOO MUCH!! This was a big help

Maybe I'm not getting this, but your last eq shows you taking the moments to the left of DE and you calculated with 5'x10k + 15'x10k - 15'x35k. I don't think you did that correctly. The second 10k load is only 10' away, not 15'.

Your videos are awesome!

why you didn't consider components of Force in DE while taking moment about A???

Wouldnt FDE create a moment when taking the moments about point A?

Hi,, i just figured out that u r taking sum of forces along x axis=Fde=cos theta and then again for y direction u r taking it cos alpha again... shouldn't it be sin alpha???

Are you sure that your moment about point n equation is right? You have (10kip)(5ft) as well as (10kip)(15ft). Shouldn't that second 10kips have a moment arm of 10ft? Starting at 14:36

isnt the joint in compression if the force exerted by the joint goes outwards (ie positive in your explanation)? (Because its exerting an opposing force to that which is exerted upon it, like Newton said?) Our lecturer explain it to us that way and im slightly confused now haha

thanks for the help but I think u made a mistake while so I ng for the moment about N. one of the downward forces of 10 you wrote with a distance of 15 when it should be 10 . but other than that great video

Great video but the volume of the audio is extremely low.

In your (iii), why does summation of Fy not include the three 10k forces as well as the Ay?

Shouldn't u analyse FNM .cus its not vertical on line NE ..when u take the moment !?..please help ..

Man you are awesome 😍

thanks for the comments. i got sloppy at the end. minus 5 points for me.

i already gave this a subsrcribe but i have got a question why r u not takin in accoutn for the 10 n forces accting at the joints when u are doing the sum of the Fy compopnets at certain point?

Problems like these can be solved usually by moments at points most of the time especially when two other members are cancelled out at that point.

at 9:46 I don't understand where you get all these numbers. I know they come from the Truss, but you just say them list them all without any explanation where they are coming from. I'm trying to do studies aboard in France and they only use letters for their equation and makes it even less clear. I was able to understand everything up to 9:46.

dont you have to take the moment around a point with in the section you have chosen?

Good effort keep up the good work!

Thanks a looot it really did help me :)

why did you do the moment in E? i though that it was in A :S

how to know which component will cause moment? I mean to say first you took vertical and then horizontal.

Amazing video 😍

This was extremely helpful. Thank you!

When you are taking the moment about N why do you have F(de) as a negative when both the x and y components are in the positive? Thank you for the videos by the way

so lovely and helpful , thanks alot!!

Hi. In 10:30 Why you didn't include members FDO and FCP in the sum of moments?

If I take the moment about point N instead of point E, will I still be able to isolate the force DE by itself? Since NE and NM will be in the same line of action (?)

Why does the verticle componant of FDE not cause a moment about A when the 10kip force acting on pont D does?

With the two equations you got could you have just done Cramer's rule with the two unknown forces set to x1 and x2

Great Video

like the video bt one question, when u took the momnt abt the pt 'A' shudnt u take the vertical and the horizontal forces due to the member DE too??

Hey structurefree, why didn't we take the y component of F(de) when taking moment about point N. Wouldn't it produce moment as well?

hello sir can you make video on method of members? please ......thank you

Hello, would it be possible to do this same problem but using the other half of the truss. I started it and got Fmn= 33.33 in tension, but i am having a really hard time finding the other two forces.

Thank you so much but i notice soomething wrong when you solve Fde the one 10 kips there must be times to 10 not 15...

+ve value for a member signifies tension action?

in the summation of moments at A, you did not include F ne because it passes through A right?

thank you! :) this is very helpful!!

looks like i was sloppy in the middle too. i put an annotation in the video.

Thanks a lot Sir for your awesome videos :'( Really thanks a lot

I got completely different answers. I don't think I did anything wrong. I got DE as -49.58k. NE as 325k and NM as 41.67k I first found the support reactions. Ax as 0, Ay as 35K, and Iy as 35k then I took the moments about point N Sum(M) at N -9xDEsin(59.036)+5x10+10x10-35x15=0 which gives me DE= -49.58k (in compression) then I took moments about point A Sum(M) at A -5x10-10x10-10x15+NEsin(67.38) NE=325k in tension After that I just took the summation of all the forces along x axis. Sum(F) along x -48.59Sin(59.036) + NM=0 which gave me 41.67k (in tension) Can anyone confirm if these answers are correct or not?.

What software are you using? Great video by the way! 👌

7hank you for our for awesome mechanics

Your moment on N, 10 kips with 15 ft. distance must replace with 10 ft.

the last moment of fde 15' instead of 10'