Radius of curvature of a bimetallic strip

drakierd

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

I need to calculate the radius of curvature of a bimetallic strip when the two strips are subjected to different temperatures. in the problem, the two metals themselves are in different temperatures. One at 180°C, other at 160°C. Anyone with good solid mechanics knowledge will do. Any suggestion will be highly appreciated.



2. Relevant equations

Define L = strip length, dL = L1-L2 at that temp. difference, and T = thickness of one metal layer. When bent to the required radius r, the inner-outer layer arc length difference due to a radius difference of T equals dL.

Thus theta*((r+T/2)-(r-T/2)) = dL, where theta = L/r.
Then LT/r = dL ==> r = LT/dL.

3. The attempt at a solution

Need help here

tiny-tim

hi drakierd! welcome to pf!
that's it!

you know T, and you can find dL/L from the given coefficients of expansion of the two metals (i assume they are given?)

shouhardo

Hi,

In my case, it is not a Bimetal strip, it is a bimaterial strip. And one material is glass and the other one is few microns Iron deposited on it. And finally the glass is 160C and the metal is 180C. And the question is that I need to know the radius of curvature of this thing. Any suggestions for that?

tiny-tim

hi shouhardo! welcome to pf!

can't you use coefficients of expansion in exactly the same way?

shouhardo

yeah I can. You are right, that's how I have to do it.