Effect of Physical Nonlinearity on Local Buckling in Sandwich Beams

This article deals with experimental, theoretical, and FE characterization of the local buckling in foam-core sandwich beams. In the theoretical approach, this phenomena is considered in a periodic formulation (unbounded wrinkle wave); a nonlinear stress—strain response of the face material is accounted for. In the FE approach, nonlinearity of the core material is also modeled. Full-field strain measurement is employed in the tests showing that the commonly used edgewise compression set-up can cause premature waviness of the faces, and therefore, nonlinear local deformations in the core layer.