# determining the stress of a beam

I have a question regarding a beam. I first consider a force applied to both ends of a rectangular beam which is perpendicular to its cross section with dimensions w (width) and h (height). The length of the beam (l) is parallel to the applied force (F).

If I wanted to find an expression for the stress, my guess would be:

$$\sigma = F/A = \frac{F}{wh}$$

But since the force is applied to both ends, should it say be, 2F? Not sure how to account for the fact that the force is being applied from both ends.

• The answer is $F/A$ not $2F/A$. Commented Mar 28, 2016 at 20:55
• Regarding your follow-up question below: how exactly is the force being applied along a direction other than the length of the column? Commented Mar 28, 2016 at 20:58
• @lemon Basically I am suppose to assume that the force is parallel to the [111] direction, and re-calculate stress and strain values. I think I might have to use moments, but I am not 100% sure. Commented Mar 28, 2016 at 21:17

If I got it right, you probably mean the stress on a column - not a beam - caused by an axial load $F$. In that case your guess $F/A$ about the stress is right, otherwise the column should be moving!