Longitudinal oscillations of the space elevator ribbon
Bibliographic record
Abstract
AbstractA space elevator could be an alternative to rockets for human access to space. Construction of a space elevator requires a material with a high tensile strength, and a low bulk density. An important aspect to consider before construction of the space elevator is the dynamics of space elevator. In this thesis, an important part of the dynamics - the longitudinal oscillations of the space elevator ribbon - is studied. Unlike previous works, a space station located at the geosynchronous altitude has been taken into account. Using discretization by assumed modes method and Lagrange approach, the equations of motion for the space elevator in the longitudinal direction are derived. These equations are nondimensionalized and then solved using MATLAB. Based on the solution of these equations, the effect of the mass of the space station on the period and amplitude of the longitudinal oscillations is examined. It is shown that if the mass of the space station increases, both the amplitude and the period of its oscillations increase. Also the effect of the change in the mass of the counterweight on the amplitude of the oscillations is studied. It is observed that the oscillation of the space station depends strongly on the mass of the counterweight. It was found that any increase in the mass of the counterweight, even by a small percentage, will result in oscillations of the space station and the amplitude of the oscillations increases. On the other hand, any decrease in the mass of the counterweight even by a small percentage will result in oscillations of the space station toward the earth, and the amplitude of the oscillations increase. Finally, the effect of the mass of the climber and its position on the longitudinal oscillations of the ribbon is studied, and the needed adjustments in the mass of the counterweight are presented. It was found that the climber as a point mass can increase the amplitude of the space station oscillations, and the amplitude of these oscillations depends on the mass and the distance of the climber from the geostationary altitude. It is also suggested that the climbers finally could become part of the counterweight or space station to provide such adjustments in the mass of the counterweight or the space station.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".