High-Order Modeling and Experimental Validation of Local Effects in Sandwich Beams

Junctions of cores with different material properties in sandwich beams are considered. Substantial local effects arise in the vicinity of the junction when the panel is subjected to a vertical load. These effects, which can not be described in the frames of the classical sandwich theory, manifest themselves in a development of bending normal stresses in sandwich faces, as well as in a rise of the transverse normal stress and variation of the shear stress in the adjacent cores. High-order modeling applied to a beam in the three-point bending revealed a significant scale of the stresses locally induced at the core junctions in the sandwich beam compared to the expected level of global stresses. The followed experimental investigation of a representative sandwich beam fully confirmed the findings of the analytical modeling.