Farkas D, Willemann M, Hyde B
Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
Phys Rev Lett. 2005 Apr 29;94(16):165502. doi: 10.1103/PhysRevLett.94.165502. Epub 2005 Apr 26.
We investigate the mechanisms of fatigue behavior in nanocrystalline metals at the atomic scale using empirical force laws and molecular level simulations. A combination of molecular statics and molecular dynamics was used to deal with the time scale limitations of molecular dynamics. We show that the main atomistic mechanism of fatigue crack propagation in these materials is the formation of nanovoids ahead of the main crack. The results obtained for crack advance as a function of stress intensity amplitude are consistent with experimental studies and a Paris law exponent of about 2.
我们使用经验力定律和分子水平模拟在原子尺度上研究纳米晶金属的疲劳行为机制。结合分子静力学和分子动力学来处理分子动力学的时间尺度限制。我们表明，这些材料中疲劳裂纹扩展的主要原子机制是在主裂纹前方形成纳米空洞。得到的裂纹扩展与应力强度幅值的函数关系结果与实验研究一致，且巴黎定律指数约为2。
