Self-driven tunneling crack arrays—a 3D-fracture mechanics bifurcation analysis
| Autor: | Martin Hofmann, U. Bahr, Herbert Balke, Thomas Linse, H.-A. Bahr, Hans-Jürgen Weiss |
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| Rok vydání: | 2006 |
| Předmět: |
Materials science
Field (physics) business.industry Computational Mechanics Fracture mechanics Structural engineering Mechanics Physics::Classical Physics Finite element method Physics::Geophysics Crack closure Mechanics of Materials Modeling and Simulation Fracture (geology) business Scaling Bifurcation Quantum tunnelling |
| Zdroj: | International Journal of Fracture. 141:345-356 |
| ISSN: | 1573-2673 0376-9429 |
| DOI: | 10.1007/s10704-006-9001-1 |
| Popis: | Tunneling cracks driven by drying in a ceramic precursor confined between two glass plates represent a simple type of three-dimensional (3D) crack pattern. They arrange themselves via mutual unloading which causes some cracks to stop whereby the remaining ones get the right spacing for further propagation. By extending a 2D-model of self-driven propagation of crack arrays, a fracture mechanical bifurcation analysis for 3D-crack patterns based on calculating the post-critical contour of the alternating bifurcation mode has been developed. Shrinkage due to drying is replaced here by a simplified thermo-mechanical model based on an effective heat flow whose related temperature field and thermal stresses drive crack propagation. By means of the finite element method, the propagation velocity and the minimum spacing between the steady-state parallel tunnelling cracks are determined. Comparison of theory and experiment suggests that propagation may be non-stationary in these experiments. The observed relation between crack spacing and layer thickness, p ~ e2/3, follows from a scaling analysis. |
| Databáze: | OpenAIRE |
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