Lamb waves for non-contact fatigue state evaluation of composites under various mechanical loading conditions
| Autor: | N. Kosmann, Gerd Busse, Dorothee Sauer, M. Rheinfurth, Karl Schulte |
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| Rok vydání: | 2012 |
| Předmět: |
Imagination
chemistry.chemical_classification Materials science media_common.quotation_subject Composite number Glass fabric Stiffness Polymer Finite element method Contact fatigue Lamb waves chemistry Mechanics of Materials Ceramics and Composites medicine Composite material medicine.symptom media_common |
| Zdroj: | Composites Part A: Applied Science and Manufacturing. 43:1203-1211 |
| ISSN: | 1359-835X |
| DOI: | 10.1016/j.compositesa.2012.03.021 |
| Popis: | Methodologies for non-destructive evaluation of mechanically induced fatigue in fibre reinforced polymers are discussed. Specimens made of non-crimp glass fabric are fatigued using three different load ratios (tension–tension, tension–compression, and compression–compression). The investigation involves two loading directions (0° and 90°) of the quasi–orthotropic composite. Based on mode conversion of air-coupled ultrasound to Lamb waves, variation in a 0 -mode velocity is measured in a non-contact and single-sided access configuration. The velocity measurements are performed within and outside the servo-hydraulic test rig used for inducing fatigue damage. Formation of cracks monitored in the transparent composite results in degradation of stiffness observed by the test rig. Decrease in a 0 -mode velocity caused by fatigue is shown to correlate closely with stiffness degradation for all loading ratios and directions. The correlation is studied by calculating a 0 -mode velocities from single-ply properties whose stiffness degradation was determined using the observed crack densities and a finite element based model. |
| Databáze: | OpenAIRE |
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