×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Double Overhanging Beam

Double Overhanging Beam

Double Overhanging Beam

(OP)
Hi

I am an apprentice engineer trying to learn about beam, and beam bending.

I have done a little presentation analysing a double overhanging beam. Please could one of you wonderful seasoned Engineers let me know if I have got it correct?

The first image is of the beam with 2 point loads of 20Kn and a UDL of 50KNm



The second image shows the moments and reactions



The 3rd image shows the shear force diagram



Finally the 4th image shows the bending moment diagram - using the areas under the various stages of the Shear force diagram



I've tried to make it as clear as possible but hope that you will be critical with your comments.

Many thanks

RE: Double Overhanging Beam

one obvious (and trivial) observation is the spans are not to scale.

one obvious problem is your reactions don't balance the applied loads ...
140kn applied, 90kN reacted.
this is something you should've done yourself.

it looks as though you've applied the 50kN/m over only 1m (not 2m as shown).

sumMa ... 4B = -80+40+100*5, B = 115kN
sumMb ... 4A = -100+40+160, A = 25kN

the rest is "trivial".

another day in paradise, or is paradise one day closer ?

RE: Double Overhanging Beam

(OP)
I thought you applied the UDL as a point load at the midpoint of the span? i.e. 50Kn x 1. Therefore there is is 90 kN applied?

Thank you for the feedback

RE: Double Overhanging Beam

you can (for the purposes of getting external reactions) replace a UDL with a point load at the centroid but the load is 50kN/m*2m.

For internal shears and moments you should carefully apply the method of cuts to the loading (as you have done).

I think you can fudge the problem to get your reactions ...
if 25kN/m applied to the RH overhang, then ...
sumMa ... 4B = -80+40+50*5 ... B = 57.5 kN
sumMb ... 4A = -50+40+160 ... A = 37.5 kN
applied load = 90 kN = sum reactions.

another day in paradise, or is paradise one day closer ?

RE: Double Overhanging Beam

(OP)
Thanks ever so much for your help

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close