# Deflection cantilever beam

## Homework Statement

How do I find an expression for the deflection at midspan for a cantilever beam loaded with a uniformly distributed load?

Illustration of beam: http://goo.gl/3SxeVZ [Broken]

## Homework Equations

$\delta = \frac{Qx^2}{24EI}(6L^2-4Lx+x^2)$

## The Attempt at a Solution

Attempt at solution: http://goo.gl/umUBkU [Broken]

My current answer is: $\frac{49QL^4}{1280EI}$, I think this is wrong. Putting $x = \frac{L}{2}$ in the elastic curve formula I get: $\frac{17QL^4}{384EI}$, I think this is the correct answer.

Last edited by a moderator:

SteamKing
Staff Emeritus
Homework Helper
You can always check your formula for the deflection by setting x = L and seeing if your result is the same as that from a beam table.

nvn
Yes, that was the mistake. I got the correct answer now: $\frac{17QL^4}{384EI}$. Thank you nvn.