Composite wood-steel beam

Normal stresses in the transformed material must be multiplied by the modular ratio n to properly account for the actual elastic modulus. The maximum steel stress in this case occurs at the top and bottom beam surfaces, and the stress must not exceed 24,000 psi.

Rearrange the flexure formula to solve for M2, the maximum moment permitted in the beam based on the 24,000 psi allowable stress in the steel: