I'm supposed to find the deflection of a beam. It's steel with a brass shell, so they have different values for E. How do I do this problem using PL/AE. Intuitively I think I should take the average, but I have no idea if that's right or not. Thanks. I should probably give some more information: the steel part is 1m x 1m and the shell is 1/4 m on all sides, so the total area of the beam is 1.5m x 1.5m. The force is applied evenly on the end of the beam. I thought maybe I should just use PL/AE for the material with the higher E value - steel - but the brass shell would have to have some effect on the deflection.