Theoretical Analysis and Experimental Investigation on Buckling of FASTMast Deployable Structures

FASTMast (Folding Articulated Square Truss Mast) deployable structure is the main bracing structure for the flexible solar array of the international space stations. This study investigates the buckling of FASTMast deployable structures. To this end, the buckling modes and the stiffness characteristics of this structure using the flex batten as an elastic bearing member were theoretically analyzed. The analytical results show that (1) the buckling mode of a FASTMast deployable structure is similar to the elbow joint movement failure when the stiffness of the flex batten is below a critical stiffness value. Once this critical stiffness is reached, the buckling mode takes on the form of Euler buckling. (2) The stiffness of the flex batten is proportional to its cross-sectional second moment of area. Furthermore, an experimental study was carried out to validate the accuracy of the theoretical analysis. The results from experimental work agree fairly well with those from theoretical analysis. The research findings herein are expected to be useful for future studies on similar structures.