Investigation of S-Shaped Cross-Section Tape Spring with Enhanced Deployment Characteristics

In recent trends, tape springs have replaced conventional hinges in space applications owing to their several advantages, such as self-deployment ability, minimum mass penalty, and frictionless operation. The conventional C-shaped cross-section tape spring has different deployment moments in an equal and opposite sense of folding. This research aims to investigate a tape spring with a novel S-shaped cross section comprising two tangential curves meeting at the center. This article analytically, numerically, and experimentally investigates the deployment characteristics of the composite tape springs. The findings confirm a significant improvement in the deployment moment and stored strain energy of the proposed S-shaped cross-section tape spring compared to a conventional C-shaped cross-section tape spring of the same mass. Also, the S-shaped cross-section tape spring shows the same deployment moments in both senses of folding due to the cross-section symmetry, which leads to lower deployment overshoot and better deployed stiffness. With these enhanced deployment characteristics, the S-shaped cross-section tape spring can replace the conventional C-shaped cross-section tape spring without any major design modification in the deployment mechanism. The insights gained from this study can be directly implemented for several tape spring-based space-borne deployable mechanisms.