Blog posts

We simulate the fracture processes of ferroelectric polycrystals in
three dimensions using a phase-field model. In this model, the grain
boundaries, cracks and ferroelectric domain walls are represented in a
diffuse way by three phase-fields. We thereby avoid the difficulty of
tracking the interfaces in three dimensions. The resulting model can
capture complex interactions between the crack and the polycrystalline
and ferroelectric domain  microstructures. The simulation results show
the effect of the microstructures on the fracture response of the
material. Crack deflection, crack bridging, crack branching and
ferroelastic domain switching are observed to act as the main fracture
toughening mechanisms in ferroelectric polycrystals. Our fully 3-D

The velocity and instability of crack motion in 2D hexagonal lattice of graphene under pure opening loads

are investigated by atomistic molecular dynamics simulations. The brittle crack along zigzag direction

in a strip can propagate supersonically at even 8.82 km/s under uniform normal loading of edge

displacements. Crack moving straightly at low speeds produces atomically smooth edges, while kinking

occur beyond a critical speed around 8.20 km/s equivalent to 65% of Rayleigh-wave speed in graphene,

 Dear Colleagues:

Happy New Year!

 The 17th U. S. National Congress on Theoretical and Applied Mechanics that will be held June 15-20, 2014 at Michigan State University, East Lansing, Michigan. (http://www.usnctam2014.org/)

I read with interest an excellent discussion about Linear Algebra in Mechanics. I am attaching Chapter I: Tensor Preliminaries from my book Elastoplasticity Theory, which includes Hill's analysis of induced tensors mentioned in the discussion.