Mode I steady-state crack propagation through a fully-yielded ligament in thin ductile metal foils
| Autor: | Wade R. Lanning, Christopher L. Muhlstein, Syed Saad Javaid, Camilla E. Johnson |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Steady state
Materials science Applied Mathematics Mechanical Engineering Linear elasticity 0211 other engineering and technologies chemistry.chemical_element Fracture mechanics 02 engineering and technology Condensed Matter Physics Elastic plastic Metal 020303 mechanical engineering & transports medicine.anatomical_structure 0203 mechanical engineering chemistry Aluminium visual_art Ultimate tensile strength visual_art.visual_art_medium Ligament medicine General Materials Science Composite material 021101 geological & geomatics engineering |
| Zdroj: | Theoretical and Applied Fracture Mechanics. 101:141-151 |
| ISSN: | 0167-8442 |
| Popis: | Steady-state crack propagation is the advance of a self-similar crack tip with a constant driving force. Though steady-state growth is often described with analytical models, it is rarely experimentally observed or characterized under quasi-static loading conditions. Thin ductile metal sheets, such as the 25.4 μm, 50.8 μm, and 127 μm thick 1235 aluminum specimens used in this study, exhibit steady-state crack propagation but cannot be characterized by conventional linear-elastic (K) or elastic-plastic (J) crack tip parameters that require contained crack tip plastic zones. Instead we used a fully-yielded plastic crack growth resistance analysis (i.e., ligament stresses were above the tensile yield stress) to identify when cracks in thin aluminum sheet specimens reached steady-state propagation conditions. At steady-state a constant, characteristic crack growth resistance, σ c was observed for each sheet thickness ( σ c 25.4 μ m = 60 MPa , σ c 50.8 μ m = 95 MPa , and σ c 127 μ m = 93 MPa ). This σ c -controlled crack growth is dramatically different from conventional linear elastic and elastic plastic crack growth because the plastic zone is uncontained and extends across the remaining ligament. |
| Databáze: | OpenAIRE |
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