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Full-field Strain Measurements for Microstructurally Small Fatigue Crack Propagation Using Digital Image Correlation Method
Published on: January 16, 2019
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Path (un)predictability of two interacting cracks in polycarbonate sheets using Digital Image Correlation.
J Koivisto1, M-J Dalbe2,3,4, M J Alava1
1Aalto University, Department of Applied Physics, PO Box 14100, 00076 Aalto, Finland.
Scientific Reports
|September 1, 2016
Summary
Digital Image Correlation tracked crack propagation in polycarbonate. Complex crack paths, including repulsion and attraction, result from local symmetry principles and material properties, making long-range prediction difficult.
Area of Science:
- Materials Science
- Fracture Mechanics
Background:
- Polycarbonate exhibits high ductility and a large Fracture Process Zone (FPZ).
- Understanding crack interaction is crucial for predicting material failure.
Purpose of the Study:
- To analyze the complex crack paths of two opposing cracks in polycarbonate.
- To elucidate the underlying principles governing crack interaction and propagation.
Main Methods:
- Digital Image Correlation (DIC) was employed to track crack propagation.
- Strain field analysis was performed to understand crack behavior.
Main Results:
- Observed complex crack paths, including initial repulsion followed by attraction between cracks.
- Demonstrated that crack propagation aligns with the principle of local symmetry, where shear mode (KII) is zero.
- Attributed crack interactions to symmetry, initial geometry, and material properties (FPZ).
Conclusions:
- Crack interactions in ductile materials are governed by local symmetry principles.
- The complex interplay of geometry and material properties complicates long-range crack path prediction.
- DIC analysis provides valuable insights into crack propagation dynamics in materials with large FPZs.
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