Crack Tip Dislocation Nucleation in FCC Solids
نویسندگان
چکیده
We present results of molecular dynamic simulations aimed at examining crack tip dislocation emission in fcc solids. The results are analyzed in terms of recent continuum formulations of this problem. In mode II, Au, Pd, and Pt displayed a new unanticipated mechanism of crack tip dislocation emission involving the creation of a pair of Shockley partials on a slip plane one plane below the crack plane. In mode I, for all the materials examined, Rice’s continuum formulation [J. Mech. Phys. Solids 40, 239 (1992)] underestimated the stress intensity for dislocation emission by almost a factor of 2. Surface stress corrections to the emission criterion brought the agreement between continuum predictions and simulations to within 20%. [S0031-9007(99)08523-3]
منابع مشابه
ductile response as the competition between Griffith cleavage and plastic shear at a crack tip. RICE and THOMSON (1974) specifically modeled the shear process as the nucleation of a dislocation from a stressed crack tip. The Rice and Thomson approach
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