Spatial Foldable Structures

A spatial foldable structure may be defined as a structure that can change its shape in threedimensions. One of the possible ways to generate spatial foldable systems is to use scissors- Eke units called duplets with multiple degrees of freedom at the joints. A novel type of scissors-like unit called a calix duplet is presented in the first part of the paper. The joint employed in a calix foldable structure is a modified Universal joint. This joint has two degrees of freedom. The geometric and kinematic properties of the calix duplet are presented. Different foldable shapes and forms may be obtained using the calix duplet including barrel vaults, grids and domes. The second part of the paper focuses on the matrix analysis of foldable systems and finite mechanisms in general. Based on an algebraic solution of interelemental constraint equations, the overall degree of freedom of a foldable system is determined. The proposed method identifies the different modes of displacement and the presence and location of bifurcation points.

• INTRODUCTION

• CALIX FOLDABLE STRUCTURES

• MATRIX MODELLING AND KINEMATIC ANALYSIS OF FINITE MECHANISMS

• CONCLUDING REMARKS

• ACKNOWLEDGEMENTS

• REFERENCES