Behavior and design of axially loaded square concrete-filled double steel tubular slender columns
Bibliographic record
Abstract
A square concrete-filled double steel tubular (CFDST) column composed of a circular core concrete-filled tube offers the advantages of both square and circular concrete-filled steel tubular (CFST) columns. However, limited tests were performed to investigate the axial performance of CFDST slender columns. This paper investigates the behavior and design of square CFDST slender columns subjected to concentric loading. A total of eight columns, including six CFDST slender columns and two CFDST short columns were tested under concentric loading. The test parameter includes the slenderness ratio of the columns and the thickness of the inner tube. The ultimate load, failure modes and axial load-deflection relationships of CFDST slender columns are presented. It was observed that square CFDST slender columns failed due to the overall buckling of the columns together with the localized buckling of the steel tube and concrete crushing. Increasing the slenderness ratio and decreasing the thickness of the inner steel tube reduced the ultimate load of CFDST slender columns. The applicability of the existing design code of CFST columns in designing CFDST slender columns was evaluated. It was found that the existing design codes significantly underestimated the ultimate loads of CFDST columns.
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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 | 0.001 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".