Stowage Analysis of a Flat Flexure Elastic Hinge for Deployable Space Structures

Abstract

This paper introduces a design framework for elastically deformable hinges consisting of two parallel flat flexures, focusing on the case where the hinge is folded by 180 deg in the stowed configuration. The authors first consider architectures in which the flexures are staggered to avoid contact so that they can be modeled independently using Euler’s elastica. They next focus on the nonstaggered case when folding can result in contact between the flexures, which they study through finite element simulations. The paper provides a set of design guidelines by rationalizing the relationship between hinge dimensions and the allowable curvature in the flexure material. For most hinge geometries applicable to deployable structures, the authors find a simple requirement for the minimum flexure length as a function of the allowable curvature in the material, Lh>10.7/κm. Their analysis also provides insight into the reaction forces necessary to keep the hinge in the folded configuration, which is useful in determining the deployment dynamics and the constraints necessary to secure the panel in place during stowage. Experimental prototypes show good agreement with the numerical predictions.