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A microscopic continuum model for defect dynamics in metallic glasses

Submitted by Amit Acharya on

Amit Acharya                       Michael Widom

To appear in Journal of the Mechanics and Physics of Solids

Motivated by results of the topological theory of glasses accounting for geometric frustration,
we develop the simplest possible continuum mechanical model of defect dynamics in metallic
glasses that accounts for topological, energetic, and kinetic ideas. A geometrical description
of ingredients of the structure of metallic glasses using the concept of local order based on
Frank-Kasper phases and the notion of disclinations as topological defects in these structures is
proposed. This novel kinematics is incorporated in a continuum mechanical framework capable
of describing the interactions of disclinations and also of dislocations (interpreted as pairs of
opposite disclinations). The model is aimed towards the development of a microscopic understanding
of the plasticity of such materials. We discuss the expected predictive capabilities of
the model vis-a-vis some observed physical behaviors of metallic glasses.

strains from the given Displacements with given X Y values by Radial Basis Function Thin Plate Spline in MATLAB

Submitted by Zuhaib Nazir on

Dear Researchers 

I have attach a text file with this message in which I have written all my code. I have applied the Radial Basis Function (interpolation) to find approximated displacements.

f = RBF(r)*a

f = given values e-g displacements to be approximate

RBF(r)= Radal Basis function (Thin Plate spline)

a= Radial Basis Function coefficient

X= x distance from the origin (given) (first column of disppoints)

Abaqus Fortran Subroutine

Submitted by SavanRGowda on

Hi Everyone,

I have now managed to run the fortran code, but it won't assign the values that I want to assign to the U(1) variable from the TXT file.

In the attached file I have the Fortran file that I am working on, the input file Subroutine1 (save it as .inp file to open in Abaqus) and the pressure file that contains the nodes and the corresponding pressure values which I want to assign through DISP Subroutine. The code below

Cohesive zone parameters - Carbon nanotube Polymer interface

Submitted by Bevan Smith on

Hi everyone

I have a question regarding cohesive zone models/laws/parameters for the interface between carbon nanotubes and polymers.  There seems to be a handful of literature on obtaining tangential (shear) cohesive zone information for this type of interface.  For example, there are a couple of experimental and molecular dynamics simulations I have found that try to obtain the cohesive zone parameters for shear.  The problem is that they are all for nanotube pullout which means that they only obtain the shear information.

2017 ASME Congress invitation-Dynamic failure of advanced materials

Submitted by L. Roy Xu on

Dr. Jun Xu and I organize  one topic on “Dynamic failure of advanced materials (fatigue failure is included also)” for 2017 ASME Congress. Our keynote speakers include a senior program manager of US Office of Naval Research and a distinguished researcher of US Army Research Laboratory. We would invite you (also your colleagues  and group members)  to submit a short abstract before ASME’s deadline March 6. More details below: 

SolidWorks

Submitted by mina rakhshi on

Hi friends,

I have a shell model in solidworks, I want to full it's volume But don't know that how do it? edgs of this model are discontinuous curve.

please help me. (picture of this model is put below)

Mina.

PhD Candidate Position in Fatigue Damage Modeling of Composite Structures

Submitted by jansen on

The Institute of Structural Analysis at Leibniz Universität Hannover invites applications for a

Scientific coworker / PhD Candidate (Salary scale E13 TV-L)

The position is available from now.  The work should lead to a PhD thesis.

Tasks:

Surface roughness evolution during early stages of mechanical cyclic loading

Submitted by ahmed.hussein on

The effect of crystal size and initial dislocation density on surface roughness evolution in FCC single crystals during the early number of cycles of mechanical cyclic loading is investigated using three dimensional discrete dislocation dynamics simulations. Crystals having size less than 2 μm show early development of surface slip localization, while larger ones show a more uniform distribution of surface steps. The surface roughness is found to increase with increasing number of loading cycles with larger crystals showing a high roughening rate compared to smaller crystals.