Bending of a varrying cross section

[rayray0071]

Recently, I had lab. In the lab we took different objects and measured their strain. One object had a varying cross section. The data for strain was recorded. Right now, I'm trying to make a stress strain graph, but the problem is my equation for stress. I don't know how i can take my moment of intertia about the z-axis. I looked all over the web. In addition, I tried contacting my TA but no success for the pass 3 days. If you can help, I would appretiate it.

Edit: I have the equations for the slopes. The problem lies with my moment of inertia.

 

[SteamKing]

The problem as shown leaves one asking a few questions. I don't know which is the z-axis.

According to the problem statement, the depth of the beam is constant; apparently only the width varies. Why don't you calculate the moment of inertia at several different locations and draw a curve of inertia versus distance from the fixed end?

 

[BadBrain]

rayray0071:

Are you certain that you need to solve for more than two dimensions?

According to your problem statement, your height (i.e., your x-axis) is of constant dimensions.

As your diagram is, according to your problem statement, viewed from above, it's your x-axis that's sticking out from the paper. The only varying dimension is the z-axis (which is the up-and-down axis on your diagram). The y-axis is, as usual, the left-right axis on your diagram.

I hope this helps.