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 cir-cular 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.