Numerical Study Using Nonlinear Finite-Element Methods Based on Green–Lagrange Strain for Dynamics and Statics of Nonequatorial Space Elevator

抄録

A space elevator consists of a climber, counterweight, and primary structure: the tether. Recently, a nonequatorial space elevator has gained attention owing to its ability to extend the construction range and avoid collisions with spacecraft in the geostationary orbit. Previous research on the tether of the nonequatorial space elevator constructed low-fidelity models, such as a rigid body or a spring–mass system, despite the complexity of its dynamics. This study newly introduced a nonequatorial space elevator model using the Green–Lagrange strain in a nodal position finite-element method and flexible multibody dynamics model for a nonequatorial space elevator formulated via the absolute nodal coordinate formulation, which ensures C¹ continuity and bending in the element. Based on the constructed models, this study investigated the primary geometrical factors in the analysis of a nonequatorial space elevator. It also examined the static effect of climber position and the dynamics of the climber's descent in a nonequatorial space elevator. The investigation revealed the cause of the higher-order oscillations occurring in the tether of the nonequatorial space elevator, which are absent in the equatorial configuration.