I. Nanomechanics of Tough
Nanostructured Metals
Atomistic
simulations show interfacial plasticity controls the strength and ductility
in
nano-twinned copper
Publications
1
T. Zhu, J. Li, A. Samanta, H. G. Kim, and S. Suresh,
ˇ°Interfacial plasticity governs
strain
rate sensitivity and ductility in nanostructured metalsˇ±, Proceedings of the
National Academy of Sciences of the USA, 104, 3031-3036 (2007). PDF
II. Nanomechanics of Plastic
Yielding in Nanopillars
Atomistic
simulations show dislocation nucleation in the surface layer of
a copper nanopillar
under compression
Publications
1 T. Zhu, J. Li, A. Samanta, A. Leach, and K. Gall, ˇ°Temperature and strain-rate dependence
of surface dislocation nucleationˇ±, Physical Review Letters, 100, 025502 (2008). PDF
III. Nanomechanics of
Incipient Plasticity during Nanoindentation
(a) 
(b)
Homogeneous
Dislocation Nucleation
(a)
2D cylindrical indenter; (b) 3D spherical indenter
Publications
1. T. Zhu, J. Li, K. J. Van Vliet, S. Ogata,
S. Yip and S. Suresh. Predictive modeling of
nanoindentation-induced homogeneous dislocation nucleation in copper,
J. Mech. Phys. Solids, 52, 691-724 (2004) PDF
2.
K. J. Van Vliet, J. Li, T. Zhu, S. Yip and S. Suresh. Quantifying
the early stages of
plasticity
through nanoscale experiments and simulations, Phys. Rev. B 67, 104105
(2003) PDF
3. J. Li, K. J. Van Vliet, T.
Zhu, S. Yip and S. Suresh. Atomistic mechanism governing
elastic limit and incipient plasticity in crystals, Nature
418, 307-310 (2002) PDF
IV. Nanomechanics of
Brittle and Ductile Fracture
a) Dislocation Loop Emission From a Crack Tip
(a)
(b)
Transition
state of dislocation loop emission in Cu
(a) atomic structure; (b) distribution of shear
displacement across the x-z slip plane
Publications
1. T. Zhu, J. Li and S. Yip. Atomistic Calculation of the Activation Energy for
Emission of
a Dislocation Loop from a Crack Tip, Phys. Rev. Lett.,
93, 025503 (2004) PDF1
PDF2
Movie download
1. 3D loop emission, (a) color-coded by coordination
number; avi
(75M)
(b) color-coded central symmetry parameter avi (75M)
(c) evolving shear displacement distribution avi (75M)
b) 3D Lattice Trapping Barriers to Cleavage
Fracture
¨¤
<112>
Opening displacement across the cleavage plane
(a)
¨¤
<110>
Opening displacement across the cleavage plane
(b)
Orientational dependence of crack front geometries
leading to
anisotropic trapping barriers in Si
Publications
1. T. Zhu, J. Li and S. Yip. Atomistic configurations and energetics of crack extension in silicon,
Physical Review Letters, 205504 (2004). PDF
2. T. Zhu, J. Li and S. Yip. Atomistic characterization of 3D lattice trapping barriers to brittle
fracture. Proceedings of the Royal Society A, 462, 1741-1761 (2006). PDF
V. Nanomechanics of
Environmental Effect on Fracture
a)
Stress- Assisted Hydrolysis Reaction of a Silica Nanorod
Molecular
pathway of stress-assisted hydrolysis reaction (color: charge variation)
Publications
1 T. Zhu, J. Li, X. Lin and S. Yip. Stress-dependent molecular pathways of silica-water reaction,
J. Mech. Phys. Solids, in press, (2005). PDF