Multiple Neutral Axes in Bending of a Multiple-Layer Beam With Extremely Different Elastic Properties

The multi-layer beam consisted of materials with extremely different elastic properties, such as silicon and Polydimethylsiloxane (PDMS), has many important applications. The Kirchhoff assumption that the straight lines normal to the midsurface remain normal after deformation does not hold any more. The energy method is used to establish a simple analytic model for multi-layered structures with extremely different elastic properties. The analytic model is validated by finite element analysis.