research
Phononic crystal with adaptive connectivity: A new approach to 'smart' materials
In recent times, mechanical metamaterials and a phononic crystals have attracted the attention of some groups, as they allow to exploit on a larger scale phenomena known from solid state physics, such as the creation of band gaps at certain frequencies. The peculiarity of metamaterials is that their effective properties emerge from the periodic geometric organization of their unit cells rather than from the constituting bulk materials. Furthermore, metamaterials can be built in any size, ranging from the nanometer to the meter scale, and out of any material to suit different needs.
Navier-Stokes model with viscous strength
In the laminar mode interactions
among molecules generate friction between layers of water that slide with
respect to each other. This friction triggers the shear stress, which is
traditionally presumed to be linearly proportional to the velocity gradient.
The proportionality coefficient characterizes the viscosity of water. Remarkably,
the standard Navier-Stokes model surmises that materials never fail – the transition
to turbulence can only be triggered by some kinematic instability of the flow. This
premise is probably the reason why the Navier-Stokes theory fails to explain
Effect of geometric parameters on the stress distribution in Al 2024-T3 single-lap bolted joints- Outstanding Paper Award Winner
The article entitled “Effect of geometric parameters on the stress distribution in Al 2024-T3 single-lap bolted joints” published in International Journal of Structural Integrity
has been chosen as an Outstanding Paper Award Winner at the Literati Network Awards for Excellence 2013.
Moredetails can be found :
Three-dimensional simulation of crack propagation in ferroelectric polycrystals: Effect of combined toughening mechanisms
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
Instability of supersonic crack in graphene
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,
Debonding simulation - XFEM fracture criterion - delamination
Hello
I am using Abaqus/CAE 6.10 to simulate a Debonding test (cohesive behavior for composite delamination).
I ran a Abaqus debonding simulation example (from Abaqus online documentation - Abaqus Benchmark Manual - 2.7.1 Delamination analysis of laminated composites).
The Abaqus/Explicit three-dimensional model with surface-based traction-separation behavior used a surface contact interaction property with:
- default Cohesive behavior