Numerical Analysis on Deployment Behaviors of Membrane Structure Systems

This paper shows numerical analysis on dynamic deployment behaviors of membrane structure models embedding inflatable tubes. To treat their nonlinearity, one kind of nonlinear elasto-dynamic analysis methods characterized by modified stiffness matrix is applied. Analyzed models were proposed for future membrane structure systems inspired by insects' metamorphoses. In this paper, we focus on a balance between two kinds of deployment forces: centrifugal forces due to rotation of a central satellite and extension forces due to inflation of embedded tubes. We present numerical results of deployment behaviors of rectangular and hexagonal membrane models. Details of the numerical method are also discussed. Numerical results of the rectangular membrane model provide that there exist minimum values of maximum strain energy of membrane elements at appropriate gas filling time for each rotation rate. This means that we could control deployment behaviors by regulation of inflation rate of embedded tubes and rotation rate of a central satellite bus. Numerical results of the hexagonal membrane model provide that the case of deployment with gas injection shows more smooth deployment behavior without local deformation. In the case of deployment without gas injection there appears to be local deformation with high strain energy density.