# Understanding of distance units in the pair_style per/pmb?

Hi,

i am using the pair_style per/pmb in my simulation and the fix indent
command. Corresponding to the user guide is

K = force constant for indenter surface (force/distance^2 units).

What does distance units mean in the sence of Peridynamics?

Using lattice sc 0.005 means, that i should scale my computed force
with 0.005^2, so that K = F / 0.005^2?

Regards

Patrick

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Hi,

i am using the pair_style per/pmb in my simulation and the fix indent
command. Corresponding to the user guide is

K = force constant for indenter surface (force/distance^2 units).

What does distance units mean in the sence of Peridynamics?

whatever you have selected through the units command.

Using lattice sc 0.005 means, that i should scale my computed force
with 0.005^2, so that K = F / 0.005^2?

this is unrelated to the lattice command.

axel.

Hi,

ok, i compute the force according the impulse with F = (m*v^2) /
(2*l). Can i use this force directly in the fix indent command?

I want to simulate the experiment in the Peridynamics with LAMMPS: A
User Guide with a force depending on the impact velocity of the indenter.

Is the force 1e17 in the example in any relation to the mass and
velocity of the indenter?

Patrick

On Tue, Sep 24, 2013 at 3:31 PM, Patrick Diehl
<[email protected]> wrote: Hi,

i am using the pair_style per/pmb in my simulation and the fix
indent command. Corresponding to the user guide is

K = force constant for indenter surface (force/distance^2
units).

What does distance units mean in the sence of Peridynamics?

whatever you have selected through the units command.

Using lattice sc 0.005 means, that i should scale my computed
force with 0.005^2, so that K = F / 0.005^2?

this is unrelated to the lattice command.

axel.

Regards

Patrick

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October Webinars: Code for Performance

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Hi,

ok, i compute the force according the impulse with F = (m*v^2) /
(2*l). Can i use this force directly in the fix indent command?

I want to simulate the experiment in the Peridynamics with LAMMPS: A
User Guide with a force depending on the impact velocity of the indenter.

Is the force 1e17 in the example in any relation to the mass and
velocity of the indenter?

please have a closer look at the documentation of fix indent. it
appears to me that there is a conceptual issue. the force is the
response to the indenter. it is moved according to the prescribed
formula, not due to time integration and thus as if it was of an
infinitely large mass. the force is the net force of the particles
interacting with the indenter.

axel.