Mechanical Behavior Study Of Coilable Space Mast

Coilable space mast is one of the basic form of deployable spacetruss system and application form of space arm, which make up of thebasis to develop the large space deployable structure. The coilable spacemast stores elastic strain energy through the elastic buckling and coilingto helix of continuous longeron on the ground, strain energy release indeploying state, restore to the final stable working state. It has attractedmuch attention and been widely researched both in home and abroadbecause of its simplicity, light weight, high package ratio, reliability andother characters.Based on the coiling process of coilable space mast, mechanicalbehavior analysis and experimental research were performed. It containstheoretical study of space configuration and pure bending test of longeronwith large rotation/deformation, the numerical analysis of the coilingprogress of a single longeron and the whole coilable mast, modal analysisof the component and whole frame structure.Firstly, according to the continuous longeron space configuration inthe coiling process, by introducing certain assumptions, pure bendingin-plane and helix state in space were studied on the basis of the theory ofnonlinear mechanics of thin elastic rod, the equilibrium condition and therelationship between the force and deformation were obtained.Secondly, in order to study the bending behavior of continuouslongeron, a mechanism which can perform a pure bending test with largerotation and deformation has been developed. Specimens made of glassfiber reinforced polymer material were tested, both material bendingperformance parameters and the geometric constraint were calculated.The damage mode of specimen was found during test, which can givesome advice to design of joint.Again, the primary coiling progress of single longeron was simulated with the nonlinear statics methods, and different coilingstrategies were evaluated. Then we take the whole mast as the researchobject and design two different coiling methods, and then makecomparison between the results. The mechanical behavior andgeometrical characteristics of coilable mast were obtained during coilingprogress.Finally, the modal analysis was carried out for the components offrame structure, and the influence of design parameters on naturalfrequencies and modes was studied next. Then modal analyses wereperformed for two frame structures with different geometry data, thevibration frequencies and modes of the structure were obtained.