Modeling the growth of LT and TL-oriented fatigue cracks in longitudinally and transversely pre-strained Al 2524-T3 alloy
✍ Scribed by L.P. Maduro; C.A.R.P. Baptista; M.A.S. Torres; R.C. Souza
- Publisher
- Elsevier
- Year
- 2011
- Tongue
- English
- Weight
- 784 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1877-7058
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✦ Synopsis
The aluminum alloy 2524 (Al-Cu-Mg) was developed during the 90s mainly to be employed in aircraft fuselage panels, replacing the standard Al 2024. In the present analysis the fatigue crack growth (FCG) behavior of 2524-T3 was investigated, regarding the influence of three parameters: load ratio, pre strain and crack plane orientation of the material. The pre strain of aluminum alloys is usually performed in order to obtain a more homogeneous precipitates distribution, accompanied by an increase in the yield strength. In this work, it was evaluated the resistance of Al 2524-T3 sheet samples to the fatigue crack growth, having L-T and T-L crack orientations. FCG tests were performed under constant amplitude loading at three distinct positive load ratios. The three material conditions were tested: "as received"(AR), pre strained longitudinally (SL) and transversally (ST) in relation to rolling direction. In order to describe FCG behavior, two-parameter kinetic equations were compared: a Paris-type potential model and a new exponential equation introduced in a previous work conducted by our research group. It was observed that the exponential model, which takes into account the deviations from linearity presented by da/dN versus K data, describes more adequately the FCG behavior of Al 224-T3 in relation to load ratio, pre strain effects and crack plane orientation.