A Large Double-Pendulum Device to Study Load, Pressure Distribution and Structure Damage During Ice Impact Tests in the Lab
Bibliographic record
Abstract
The design and functioning of a new impact device is described, where its eventual intended use is the study of damage associated with pressure distributions arising from ice impacts on ships. The large apparatus is a double-pendulum type device that is capable of achieving fairly high impact energies and velocities while remaining relatively ‘compact’ with respect to the confines of the laboratory space that is available. For example, at a drop angle of 35o from vertical for each pendulum the impact energy and relative velocity are ~ 31 kJ and 5.32 m/s respectively. Conical-shaped ice samples, one meter in diameter are held in a cylindrical ice holder that attaches to one arm of the double pendulum. For one type of test a unique instrumented panel (Impact Module), that records load and high spatial resolution pressure distribution during impacts, attaches to the opposite pendulum arm. For another test type the Impact Module is replaced by ship grillage (full-scale or reduced scale) so that ice impact tests can be performed that cause damage to the grillage. The pendulum arms are designed in a manner such that no rotation of the colliding masses occurs during tests. The effective masses of the colliding objects can be adjusted by adding or removing heavy metal plates. Similarly, the drop angles of the pendulum arms can be adjusted to achieve a range of impact velocities. These two adjustable features enable a variety of impact velocities and energies to be obtainable and allow for some degree of parameter-based study where either velocity or energy is fixed while the other is varied. To date a number of tests have been performed involving ice impacts on the Impact Module. Some representative sensor data that includes a few examples of the ice pressure distribution from one test are presented.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.010 | 0.002 |
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".