Development of a Cubic Core Lightweight Panel Using Origami-Kirigami Engineering

Honeycomb core panels are commonly used in industry as lightweight structures. However, because the bond between the face plate and the regular hexagonal core is weak, there are strength problems, such as heat and shear loads. In this study, a new cubic core panel was developed as an alternative to a honeycomb core panel. Unlike conventional honeycomb core panels, cubic cores can be processed from a single flat plate by punching and bending. Through the square contact area between the face plate and the cubic core, a double-bond integral panel structure was assembled using glue and rebates. The cubic core panel had a higher bending stiffness and bonding strength than the conventional honeycomb panel. A three-point bending test was performed on the processed cubic core panel. The relationship between the bending load and the deformation of the cubic core panel was determined. The curved part of the cubic core panel can be easily processed by cutting out a part of the material on one side of the cubic core panel in accordance with the lightweight structure of the curved part. A design formula for the curved part of the cubic core panel was derived using the curvature radius and curvature angle of the actual curved structure. A cubic core molding system was investigated using the parallel movement characteristics of the four-bar link mechanism for future mass production. An important design factor for practical use was obtained by deriving the relational expression between the bending load and plastic displacement.