Convert the two-material beam to a single material (aluminum in the follow example) and determine the stresses in the transformed beam. Then convert the stress of the converted material back to the original material.
Using the dimensions of the transformed beam, solve for the theoretical neutral axis location (measured from the bottom of the beam) and the moment of inertia with respect to this neutral axis.
FBDs:
Combining,
From σ = My/I and the above relationship, the stresses in the beam per unit load are
and
