Rigorous Analysis of Energy Conservation during Dynamic Deployment of Elastic Thin-Shell Structures

This paper studies the dynamic deployment of cylindrical thin-shell structures with open cross-section and attached to a rigid support. The structures are elastically folded and then released. Previous experiments have shown that the total energy of these structures decreases while a fold moves back and forth along the shell, which was explained in terms of energy losses related to the fold “bouncing” against the boundary. This paper uses a rigorous numerical simulation, based on an in-house isogeometric shell finite element code that simultaneously eliminates shear locking and hourglassing without any intrinsic energy dissipation, to show that the total energy of the system is conserved during deployment. The discrepancy with the previous results is explained by showing that en- ergy transfers from low-frequency, “rigid body” modes to higher frequency modes, which were not measured.