Variable Curvature Composite Lattice for Space Applications

In space applications, deployable systems require a structure that can reliably change from a compact package state for launch to a great length or surface area once in orbit. Morphing composites are being increasingly utilized in space deployables due to their potential to be lightweight, load bearing, self-actuating and multi-functional. This study is focused on a new type of morphing composite lattice that can change its shape from a compact stowed state to a straight extended state to a curved extended state. This three-step state change is achieved by cutting slots into the lattice strips between the fastener positions for the straight and curved configurations. A prototype of the variable curvature lattice is developed, which informed the design of a lattice that can curve in two directions. The deployment force of this lattice is tested, as well as the force required to curve the lattice in both directions. Testing showed that the deployment force of the variable curvature lattice is less than a conventional lattice due to the slots cut into the strips. Additionally, the force required to curve the lattice is greater than the deployment force of the structure due to increased friction between the lattice elements.