Flexural Performance and Moment Connection of Concrete-Filled GFRP Tube–Encased Steel I-Sections
Bibliographic record
Abstract
A hybrid system, concrete-filled fiber-reinforced polymer (FRP) tube (CFFT)-encased steel I-section, is introduced. The embedded steel section enhances flexural strength and stiffness, and provides a pseudoductile behavior. It also facilitates connection of the CFFT member to footings or other members. Phase I of the experimental program addresses the flexural behavior of the system through ten beam specimens, including steel and CFFT control specimens. The glass fiber-reinforced polymer (GFRP) tubes varied in thickness and laminate structure. The steel section enhanced performance considerably, especially pseudoductility, in tubes with cross-ply laminates, in which a significant sustained reserved strength remains stable over large deflections on fracture of the tube. CFFTs with angle-ply tubes showed a considerable inherent ductility on their own, in which case, adding the steel section enhanced strength and stiffness only. Phase II addresses a moment connection through five cantilever tests. The connections consist of steel base plates welded to the steel sections, which are embedded into the CFFT members at various length (Ls)-to-span-length (L) ratios ranging from 0.1 to 1.0. Three distinct failure modes are observed. At (Ls/L) ratios of up to 0.17, premature bond failure occurs. At ratios of 0.17 to 0.47, the CFFT member achieves flexural tension failure of the tube just beyond the free end of the steel section. Beyond a 0.47 ratio, the full plastic hinge capacity is developed at the fixed end. A simple design-oriented model that predicts strengths at the full range of (Ls/L) ratios is developed and validated.
Stored with the screening record, where it is evidence for the labels above.
How this classification was reachedexpand
The three-model screen
all 5,600 screened works →All three models called this out of scope.
Structural testing of concrete-filled FRP tube sections; civil engineering.
The study tests the structural performance of concrete-filled composite members.
Structural engineering tests of composite beam systems; domain construction research.
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) | 0.002 | 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".