Failure mechanism map for bending wood-based honeycomb sandwich beams with starch-impregnated core

The research results describing damage to wood-based lightweight panels, in which slender core cells are made of paper impregnated with modified starch, have not been encountered yet. Such solutions can benefit the circular economy era, especially in the automotive and furniture industries. The research aimed to develop failure mechanism maps for thin-walled sandwich panels consisting of wood-based facings separated by a honeycomb core of paper impregnated with modified starch. For this purpose, beams with three different facings and two types of core in two directions of orthotropy were subjected to three-point bending. It was verified that the thickness of the facing determines the strength and stiffness of the honeycomb panels, that the impregnation of the core with modified starch causes a slight deterioration in the strength and stiffness of the beams, and that the dominant type of beam failure is shear damage to the thin-walled core. There were no cases of damage to beams as a result of face indentation or face yielding.