# Homework Help: Shear Forces and Bending Moments in Beams

1. Nov 11, 2007

### mit_hacker

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

(Q) A beam 4m long is supported at the left hand side by a hinge support and on the right by a roller support. It is under a non-uniform load intensity throughout by a load intensity given by:

w = 25Cos(pi x/8)kN/m.

Write equations for the shear force and the bending moments for any section of the beam.

2. Relevant equations

F= -∫▒w
M=-∫▒F

3. The attempt at a solution

I can easily apply the above formulas and integrate.

The shear force comes to -200/π Sin(πx/8).
Similarly, the Moments come to -400/π^2 Cos(πx/8)

But at the back of the book, there is also the constant term along with the term obtained by the integration.

Last edited: Nov 11, 2007
2. Nov 11, 2007

### PhanthomJay

You've got to look at the boundary conditions to get the constants. What do you know about the bending moment at each support?

3. Nov 11, 2007

### mit_hacker

Ahhhhhhhhh!!!

That was so simple?!?!?!?!?:rofl:

I can't believe that I didn't see it! Thanks a lot for your help PhantomJay!!