Folded Sandwich Structures
A new type of structural form has been developed that enables ultra-light sandwich constructions at architectural scales. They are termed folded sandwich structures and are created by attaching faceted inner and/or outer face sheets to a folded plate core pattern. The faceted faces provide two major benefits over traditional curved-face sandwich construction: they enable strong, continuous edge connections between core and face layers; and they allow unbent, rigid sheet materials such as metals and composites to be assembled into complex curved geometries. Further information: Espacenet.
Morphing Sandwich Structures
Morphing sandwich structures are a sub-class of folded sandwich structures that have rigid-foldable patterns introduced into face sheets such that the core and face layers have compatible kinematic mechanisms. Several types of morphing plate structures have been proposed that consist of layered assemblies of Miura patterns. The proposed mechanism is created by using a single face unit per two core units. This locates the free face hinge to a core ridge location when deployed, which greatly simplifies locking mechanism design and load transfer. Below is a video demonstrating self-folding and deployment of a steel prototype.
The V2 mechanism Miura core pattern can be replaced with Miura-derivative geometries to generate different morphing curvatures. Disc, cylindrical, and conical geometric envelopes can be generated with a Miura-derivative cores. A continuous core (Type 1) or continuous face (Type 2) can be used for cylindrical and conical variants. Further information: doi:10.1016/j.engstruct.2015.03.019.