Design and Development of Lightweight Sandwich Structures with Innovative Sheet Folded Cores

In this paper, use of folded patterns as core structures for paper-based flexible wall panels and floorboards building materials was investigated. Effect of changing the geometrical parameters/conditions of the Chevron and the Mating Surfaces Chevron (MSC) patterns on panel core structure performance were studied, aim is to achieve high compressive strength and equal bending stiffness in both the longitudinal and perpendicular directions of the laminated core. Three folded core configuration were considered namely; a 3:1 aspect ratio Chevron pattern, a 1:1 aspect ratio MSC pattern with glued mating surfaces, and 1:1 aspect ratio MSC pattern without glued mating surfaces. Experimental study of the mechanical properties of the folded structures was focused on flexural rigidity derived from three point bending tests, and the structure load bearing capacity derived from static compression test, with a main objective of developing a panel with folded core structure of a specific pattern and geometry that provides high compressive strength and equal flexural rigidity in both longitudinal and perpendicular directions of the folded structure. Test results indicated that panel with core structure of 1:1 aspect ratio MSC folded pattern with glued mating surfaces provided sandwich structure of equal flexural rigidity in both the longitudinal and perpendicular directions and higher compressive strength, where, the applications for such high performance lightweight structure produced at much reduced cost are numerous.