Optimization of Perfect and Imperfect Ring and Stringer Stiffened Cylindrical Shells with PANDA2 and Evaluation of the Optimum Designs with STAGS
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Ring and stringer stiffened perfect and imperfect angle-ply cylindrical shells under combined axial compression and in-plane shear are optimized with a program called PANDA2 for the minimum weight design of stiffened panels, and the optimum designs are then evaluated with use of a general purpose finite element code called STAGS. The good agreement between PANDA2 and STAGS predictions for the nonlinear collapse of imperfect stiffened shells justifies the use of PANDA2 for preliminary design. A new PANDA2 processor called STAGSUNIT automatically generates STAGS input files for cylindrical panels and shells with both stringers and rings that have various open cross sections such as Blades, Zees, Jays, Tees and Is. In STAGSUNIT the edge conditions are formulated so that STAGS models of subdomains of a long cylindrical shell with many stiffeners can be constructed that do not have artificial prebuckling stress concentrations near the edges that might significantly affect predictions of bifurcation buckling and nonlinear collapse of the subdomain. Many STAGS models of optimized shells and subdomains of shells with Blade, Zee, and Tee stiffening are generated and explored, both with respect to linear bifurcation buckling and nonlinear collapse. The behavior of shells with an initial imperfection in the form of a general buckling mode of the imperfect shell is described from a physical point of view. Some difficulties encountered during this project are described.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 0.000 |
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 it