13th International Conference on Fracture June 16–21, 2013, Beijing, China -10- 5. Conclusive remarks In this paper crack growth behaviors and fracture in α-Fe under different temperatures through molecular simulations have been investigated using Large-scale Atomic Molecular Massively Parallel Simulator code. The mode I crack growth behaviors of an edge crack specimen under constant strain rate control at different temperatures have been investigated. A new image enhancement technique has been proposed to multiply the stripes of dislocation slip bands. It has been found that the temperature significantly affects the crack growth rate. As the temperature increases, the crack growth decreases. The results show that the mechanisms at the crack tip are sensitive to temperature and the boundary conditions. The simulation results show that the crack growth behavior under cyclic loading was related to temperature, loading mode and cyclic loading period. We performed atomistic simulations to study the relationship between RDF and crack growth behavior under a wide range of temperatures. Based on thermal activation theory and simulation results, the effect of temperature on crack growth can be taken into account by an expression in an exponential function form which describes crystal plasticity. The coefficent and index values in expression were determined by the RDF peak value obtained from atomistic simulations. The simulation results show that the crack growth process is highly dependent on the temperature. References [1] Wiki - Wikipedia, the free encyclopedia:en.wikipedia.org/wiki/Wiki [2] J. L. Rempe and D. L. Knudson. High Temperature Thermal and Structural Material Properties for Metals used in LWR Vessels. Proceedings of ICAPP 2008. Anaheim, CA USA, June.2008. [3] Ryosuke Matsumoto, Michihiko Nakagaki, Akihiro Nakatani and Hiroshi Kitagawa. MOLECULAR-DYNAMICS SIMULATION OF CRACK GROWTH WITH CRYSTAL NUCLEATION IN AMORPHOUS METAL. European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2004. [4] Yuan Gao, Cheng Lu, Guillaume Michal, Anh Kiet Tieu. A Study of Crack Propagation in BCC Iron by Molecular Dynamics Method. Key Engineering Materials, 385-387, 2008,453. [5] Inga Ringdalen Vatne, etc..Quasicontinuum simulation of crack propagation in bcc-Fe. Materials Science and Engineering A 528 (2011) 5122–5134. [6] V.A. Borodin, P.V. Vladimirov. Molecular dynamics simulations of quasi-brittle crack development in iron. Journal of Nuclear Materials 415 (2011) 320–328 [7] Ya-Fang Guo, Dong-Liang Zhao. Atomistic simulation of structure evolution at a crack tip in bcc-iron. Materials Science and Engineering A 448 (2007) 281–286. [8] M.F. Horstemeyer, D. Farkas, S. Kim, T. Tang, G. Potirniche. Nanostructurally small cracks (NSC): A review on atomistic modeling of fatigue. International Journal of Fatigue 32 (2010) 1473–1502 [9] Tian Tang, Sungho Kim, J.B. Jordon, M.F. Horstemeyer , Paul T. Wang. Atomistic simulations of fatigue crack growth and the associated fatigue crack tip stress evolution in magnesium single crystals. Computational Materials Science 50 (2011) 2977–2986. [10] Tian Tang, Sungho Kim, M.F. Horstemeyer. Fatigue crack growth in magnesium single crystals under cyclic loading: Molecular dynamics simulation. Computational Materials Science 48 (2010) 426–439. [11] D. Terentyev, E.E. Zhurkin, G. Bonny.Emission of full and partial dislocations from a crack in BCC and FCC metals:An atomistic study. Computational Materials Science 55 (2012) 313–321. [12] Yue Fan, Akihiro Kushima, Sidney Yip, and Bilge Yildiz. Mechanism of Void Nucleation and Growth in bcc Fe: Atomistic Simulations at Experimental Time Scales. PRL 106, 125501 (2011) PHYSICAL REVIEW LETTERS.
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