The in-plane and out-of-plane stress constraint factors and K − T − Tz description of stress field near the border of a semi-elliptical surface crack
✍ Scribed by Junhua Zhao; Wanlin Guo; Chongmin She
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 507 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0142-1123
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✦ Synopsis
The elastic T-stress and stress intensity factor K for semi-elliptical surface cracks have been investigated in elastic plates by detailed three-dimensional finite element calculations. The distributions of normalized K and T-stress have been obtained along the crack font with aspect ratios (a/c) of 0.2, 0.4, 0.5, 0.6, 0.8 and 1.0, and far-field tension and the effect of Poisson's ratio have also been considered. The normalized K increases and the normalized T-stress decreases with the increase of Poisson's ratio v. For v = 0.3, the normalized K gradually increases in the range of crack face angle / P 22.5°and decreases in the range of / 6 22.5°with increasing a/c. When / rises to 90°, the K values tend to maximum for various a/c. The normalized T-stress increases in the beginning and then decreases with the increase of / except for a/c = 1.0. By fitting the numerical results with the least squares method, empirical formulae have been given for the convenience of engineering applications. Combining with the corresponding out-of-plane constraint factor T z , the three-parameter K À T À T z approach has been provided, which can accurately describe the stress field around the crack front.