# Homework Help: How to treat moment release in FBD

1. Dec 5, 2008

### jmarcian

1. The problem statement, all variables and given/known data

from book
"The compound beam ABC shown in the figure has a guided support at A and a fixed support at C. The beam consists of two members joined by a pin connection (i.e moment release) at B. find deflection 'del' under the load P"

http://photos-a.ak.fbcdn.net/photos-ak-snc1/v688/183/78/25803658/n25803658_38292392_5314.jpg [Broken]

2. Relevant equations

i guess just knowing your FBD!

3. The attempt at a solution

http://photos-b.ak.fbcdn.net/photos-ak-snc1/v688/183/78/25803658/n25803658_38292393_5680.jpg [Broken]

sorry but the images are reversed, i figure we are all smart people and can see the mirror images in our minds. so in my drawing i broke the beam at the couple, and drew two equal and opposite moments, is this correct? because the moment at the couple should be zero, right? and having two opposing moments would cause that. please let me know if this is right! thanks!
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

Last edited by a moderator: May 3, 2017