How do you analyze bending stresses in composite beams made of different materials?

Use the transformed section method: convert the section to an equivalent homogeneous section using modular ratio n = E₂/E₁. The transformed width = n × original width. Find the neutral axis of the transformed section, calculate I, and use σ = My/I. Back-transform stresses by multiplying by modular ratio for the stiffer material. This applies to reinforced concrete and bimetallic strips.