The finite element method has employed to simulate the laser thermal cracking process for brittle materials. The varieties of temperature and thermal stress distributions around the crack tip were studied. The effect of cracking parameters, i.e. laser power, focus moving speed, plate thickness, crack length, cooling effect¡K etc., on the crack propagation has also investigated.
The stress intensity factor around crack tip is considered as the key parameter to dominate the crack propagation. The thermal-plastic-elastic finite element model was employed to simulate the temperature and stress distributions. The strain energy release rate and stress intensity factor solved from virtual crack closure technique and displacement extrapolation method are employed to illustrate the crack state in this study. Five crack length models were used to show the stress intensity factor variations around the crack tip. Numerical results indicate that the head flux on the surface, substrate thickness and adopting cooling sources may affect the crack propagation, crack delay significantly. The results in this study also demonstrate the feasibility of employing finite element method in the exploring crack propagation mechanism in laser thermal cracking process.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0903110-130243 |
| Date | 03 September 2010 |
| Creators | Lin, Tzu-hsiang |
| Contributors | Der-min Tsay, Ying-chien Tsai, Yung-chuan Chen, Shyh-chour Huang, Jao-hwa Kuang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0903110-130243 |
| Rights | unrestricted, Copyright information available at source archive |
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