Issue 35

A. Tzamtzis et alii, Frattura ed Integrità Strutturale, 35 (2016) 396-404; DOI: 10.3221/IGF-ESIS.35.45 403 C ONCLUSIONS model with the ability to perform fatigue crack growth analysis taking into account the local material behavior at specific locations in an aluminum 2024 T3 FSW Heat Affected Zone is proposed. To simulate the local material behavior in the HAZ without the effect of weld residual stresses, the reference 2024 T3 aluminum alloy was subjected to specific overaging conditions. The obtained overaged materials have very similar microstructural characteristics and mechanical properties to the HAZ material. The analytical results obtained with the model showed that it can satisfactory predict crack growth rates of the material with local HAZ characteristics. ACKNOWLEDGMENTS his research has been co-financed by the European Union (European SocialFund - ESF) and Greek national funds through the Operational Program"Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: Heracleitus II. Investing in knowledge society through the European Social Fund. R EFERENCES [1] Paris, P., Erdogan F., A Critical Analysis of Crack Propagation Laws. Journal of Fluids Engineering, 85 (4) (1963) 528- 533. DOI:10.1115/1.3656900 [2] Rice, J.R., Mechanics of crack tip deformation and extension by fatigue. In fatigue Crack propagation. Special Technical Publication, American Society for Testing and Materials STP 415 247-309 (1967). [3] Weertman, J., Rate of growth of fatigue cracks calculated from the theory of infinitesimal dislocations distributed on a plane. International Journal of Fracture Mechanics, 2 (2) (1666) 460-467. DOI 10.1007/BF00183823. [4] McClintock, F.A., On the plasticity of the growth of fatigue cracks. Fracture of solids, 20 (1963) 65-102. [5] Wu, S.-X., Mai Y.-W., Cotterell B., A model of fatigue crack growth based on Dugdale model and damage accumulation, International Journal of Fracture, 57 (3) (1992) 253-267. DOI: 10.1007/BF00035077. [6] Shi, K.K., Cai L.X., Chen L., Wu S.C., Bao C., Prediction of fatigue crack growth based on low cycle fatigue properties. International Journal of Fatigue, 61 (0) (2014) 220-225. DOI:10.1016/j.ijfatigue.2013.11.007. [7] Chen, L., Cai, L..X., Yao, D., A new method to predict fatigue crack growth rate of materials based on average cyclic plasticity strain damage accumulation. Chinese Journal of Aeronautics, 26 (1) (2013) 130-135. DOI:10.1016/j.cja.2012.12.013. [8] Pandey, K.N., Chand, S., An energy based fatigue crack growth model, International Journal of Fatigue, 25 (8) (2003) 771-778. DOI:10.1016/S0142-1123(03)00049-5. [9] Kermanidis, A.T., Pantelakis, S.G., Fatigue crack growth analysis of 2024 T3 aluminium specimens under aircraft service spectra. Fatigue & Fracture of Engineering Materials & Structures, 24 (10) (2001) 699-710. DOI: 10.1046/j.1460-2695.2001.00435.x. [10] Reifsnider, K., Kahl, M., Effect of local yield strength gradients on fatigue crack propagation, International Journal of Mechanical Sciences, 16 (2) (1974) 105-119. DOI:10.1016/0020-7403(74)90080-0. [11] Scialpi, A., de Filippis, L.A.C., Cavaliere, P., Influence of shoulder geometry on microstructure and mechanical properties of friction stir welded 6082 aluminium alloy, Mater Design, 28 (2007) 1124–1129. DOI:10.1016/j.matdes.2006.01.031. [12] Cavaliere, P., Nobile, R., Panella, F.W., Squillace, A., Mechanical and microstructural behavior of 2024-7075 aluminium alloy sheets joined by friction stir welding, Int J Mach Tool Manufac, 46 (2006) 588–594. DOI:10.1016/j.ijmachtools.2005.07.010. [13] Ceschini, L., Boromei, I., Minak, G., Morri, A., Tarterini, F., Effect of friction stir welding on microstructure, tensile and fatigue properties of the AA7005/10 vol.%Al2O3p composite, Compos Sci Technol, 67 (2007) 605–615. DOI:10.1016/j.compscitech.2006.07.029. [14] Tzamtzis, A., Kermanidis, A. T., Improvement of fatigue crack growth resistance by controlled overaging in 2024-T3 aluminium alloy, Fat. &. Fract. Eng . Mat and Struct., 37(7) (2014) 751-763. DOI: 10.1111/ffe.12163. [15] Budiansky, B., Hutchinson, J.W., Analysis of Closure in Fatigue Crack Growth. Journal of Applied Mechanics, 45(2) A T