A study of flattening process of deployable composite thin-walled lenticular tubes under compression and tension

Carbon fiber reinforced polymers (CFRP) laminates are extensively employed to manufacture the deployable composite thin-walled lenticular tubes (CTLTs). This paper presents a comparison of experimental and numerical and analytical results of compressive and tensile flattening types of deployable CTLTs. Firstly, a compressive flattening model created by ABAQUS was introduced to obtain its strain and stress of each ply of composite tube. Secondly, compressive flattening experiments were performed for CTLT specimens to explore compressive flattening mechanism of CTLTs. Then, the numerical simulation methods to simulate the compressive flattening of CTLTs were verified by comparing measurements and corresponding numerical results. Thirdly, analytical models are employed to predict the flattening process of CTLTs under compression. Lastly, for the tensile flattening process of CTLTs, the numerical simulation method and corresponding experiments and theoretical results are respectively also carried out with aim of revealing mechanical properties of CTLTs under tension. The flattening process of CTLTs can be considered to be a nonlinear deformation and small strain process. For the compressive flattening, the maximum compressive force, displacement and strain are 98N, 60mm and 0.29%, respectively. For the identical tensile flattening, the maximum tensile force, displacement and strain are 550N, 42.5mm, 0.53%. respectively. It is found that the compressive flattening way is a better choice in the design of the actuated mechanism.