# Talk:Shear Force and Bending Moment Diagrams

--41.133.21.67 09:37, 14 October 2012 (UTC)This was absolutely brilliant. Thank you, as an architect trying to teach tructures to architecture students, it was simply put and concisely explained. Graphic quality to the article is fantastic. Architects understand pictures! Many Thanks Ken Stucke. South Africa.

I found this far more useful than the textbook and the lecture notes I have. My thanks to you.

Thanks a lot sir, for such an interesting and useful material.--Rajeev

Some very usefull information. would be nice if you wrote some about Torsional moments as well.
-Thanks. sorry, I never did anything on torsional moments.

--Mack paris 10:33, 14 October 2010 (UTC)could you please add something about moments and couple along with the diagram.--Mack paris 10:33, 14 October 2010 (UTC)

-Sure. Hope what I added helps. Taltastic 23:24, 17 October 2010 (UTC)

The explanation provided here with simple and easy to understand figures are absolutely brilliant. Looking forward to your continuation, sir. Please do go ahead sir. Your article has conveyed the ideas way easily than when I tried even harder to understand what my sir was trying to explain, by complicating it in class.

By the way sir, just 1 doubt. " Taking moments about A (clockwise is positive): 40·2 - 20 + 6·R2 = 0 "

This is the line I've picked from your example about point moments. I believe the equation should be: 40*2 - 20 - 6*R2 = 0

Thanks again for this brilliant article. Looking forward..

- Deepak.ail 10:49, 18 October 2010 (UTC)

--Thanks a lot for the positive feedback, and thanks for calling me Sir :) And yes, you were right about my mistake, thanks for noticing. Taltastic 21:33, 19 October 2010 (UTC)

Fantastic article, really helped me with pre exam study.

--== Thanks! ==

Really Interesting! I am going to university this year to study civil engineering and find this article very helpful. Is this a writing error?

"If you slice the cube in half halfway up"

BTW This article is written very well. All you need to know really is some basic mathematical concepts (e.g. how to draw a diagram) and the concept of moments. Please continue to make more articles. I personally (considering my career) would prefer any article related to civil engineering.

Thanks once again! :)

--92.15.215.59 18:00, 14 January 2011 (UTC)

Thanks for the nice message! nope, not an error. I may continue writing articles one day, right now I have to find a job... Taltastic 14:34, 15 January 2011 (UTC)

## Doubt.

Hello Sir,

I have a doubt to draw Shear force Diagram for a beam when a force is acting at the point. For instance, in the example, Why do you have to consider both E and E' while drawing SFD??

- So let me first check something, you understand how the method I have taught works. i.e. you know which situations to take the shear force before and after, and you know which situations to it just at the point. However you don't understand WHY you are doing this. I'm afraid I can't think of a good way of explaining why, other than to say that at C the point force of 40N up, causes the shear force to increase by 40N (i.e. go from -10N to 30N. so from c to c')Taltastic

## Thanks!

You nailed it!! Thank you for the effort..

## Thanks a ton.....

This is worth reading and remembering......All that what looked so complicated in the school back then, you have nailed it here so effectively.....that it gets registered easily in the users' minds. Thanks for your help.

## Thanks

Thank You so much, It helped me recall the basics I learnt at school.

i found this extremely easy to understand in comparison to most websites and textbooks (pdfs included) THANKS =)

## Thanks an Ocean...

I like this article. I understand shear and bending moments diagrams clearly now.

## Shear Force at Point

In the example under the heading "Basic Shear Diagram" you have a point force of 20N acting down. I understand the need to sum the forces before and then after the 20N force which gives you a straight vertical line on the diagram. My confusion is involving what is the shear exactly at that point of the 20N acting down? Since according to the diagram which displays the strait vertical line starting at 10N at the top and -10N at the bottom, would the Shear force exactly on the 20N point be 20N, 10N (as it is before the force has acted), -10N (as it is after the force has acted) or 0N (Since the line crosses 0)? Thank You! --Bmullin (discusscontribs) 01:54, 12 February 2013 (UTC)

I'll be honest, I'm not an expert on the topic. However, I suspect that on the 20N point, you would say that there is a shear force transition from -10N, to 10N. (So the shear force isn't a single value, like -10N,0N,10N or 20N). Taltastic (discusscontribs) 01:48, 14 February 2013 (UTC)

## What is shear force?

As stated in the example here, it is understandable that when the force is applied to an object it is redistributed all over. However the distribution cannot be linear as suggested in diagrams, having an instant rise or fall at a definite point, in an elastic case, it is very hard to visualize. The only explanation of this phenomena could be that we consider the object totally inelastic for consideration of the Shear Force. Hence rendering it to be proofing against inelastic failure. Please elaborate if this is the case or if there is another explanation.

Thank You!

You make an interesting observation...To quickly answer your question - no, you will still get a uniform shear force distribution even when the material is elastic! I think I gave too brief of an explanation on page on what shear force is, so I will write a better one (with pictures). Give me a week or 2 to do it :) Taltastic (discusscontribs) 15:13, 20 May 2013 (UTC)

why are the right portions covered with paper? I mean why the loads towards the right hand side neglected while considering the moments?

Moments and bending moments are 2 different things. When you work out moments, you look at both sides. But when you work out bending moments you only look at one side. I've chosen the left side. Let me know if that doesnt answer your question/you have more questions Taltastic (discusscontribs) 20:19, 12 November 2013 (UTC)

Hello Sir! This article was simply amazing, helped me a lot. But i have doubt,

Y do we have to calculate shear force before and after at a particular point? And What does maximum bending moment indicate?

The shear force before a point is different to the shear force after a point, sometimes. Which is why you have to calculate both, and show them on the diagram. To try to answer your next question: In all the examples I've shown in this document, you can imagine that the beam will bend under the forces/moments its experiencing. This is because the forces are producing a bending moment at a given point on the beam. It is that bending moment which causes the beam to bend at that point. The more bending moment there is at that particular point, the more the beam will bend at that particular point.Taltastic (discusscontribs) 20:54, 27 November 2013 (UTC)