Measuring fracture toughness of piezoceramics by vickers indentation under the influence of electric fields
Bibliographic record
Abstract
The Vickers indentation technique was used to determine the apparent fracture toughness of PZT-4 piezoceramic under the influence of electric fields. The toughness was measured in terms of the mechanical strain energy release rate. Using the analytical mechanical strain energy release rate for an infinite piezoelectric medium with a center crack and far field in-plane mechanical and electrical loadings, the mechanical strain energy release rate was obtained for Vickers indentation. The effect of the electric field was included. The proposed formula was evaluated with the experimental results. It was found that the fracture toughness depended on the indentation force. Vickers indentation tests were also performed on depoled PZT-4 specimens; these test results indicated that the fracture toughness of depoled PZT-4 was also dependent on the indentation force. To eliminate the indentation force dependence, a modified stress intensity formula based on Vickers indentation was proposed.
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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 | 0.001 | 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 | 0.001 |
| 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".