howto change youngs modulus during simulation

Submitted by knoe_ph on Tue, 06/05/2012 - 16:04

Hallo,

quick question:

is it possible to change properties like youngs modulus (which I defined right at the start of my simulation with a fix_property/global command) at a later stage of simulation?

I first tried it by simply unfixing the previous command and then redefining it again with fix_property/global and the new value. This procedure resulted in multiple "WARNING: Dangerous build in triangle list" and as a consequence my particles disappeared out of my simulation box.

Then I tried another approach by using the fix_adapt command to change my Youngs modulus, which led to an error message: "replacing a fix, but new style != old style".

Now I'm wondering if it is possible at all, or if I did something else wrong?

Kind regards,
Philipp

Philippe's picture

Philippe | Tue, 06/05/2012 - 16:50

Youngs Modulus is bound to the particle type, so you could assign a new particle type via the

set

command to the particles.

greetz
Philippe

knoe_ph | Tue, 06/12/2012 - 09:58

Hallo,

i tried to assign a new particle type via "set group all property/peratom youngsModulus 90.e9 90.e9" like it is described in the documentary. It results in an error message: "could not identify the per-atom property you want to set".

I'm not sure if this is the correct way to assign the new particle type because originally i defined my youngsModulus to a fix_property_global command.

I guess theres a mistake in my syntax here.

Kind regards,
Philipp

moritzhoefert | Tue, 06/12/2012 - 16:27

Hi Philipp,

how about defining two atom types with

create_box 2 wholeSystemRegion

and accordingly two different Y values, nus, etc

fix m1 all property/global youngsModulus peratomtype 1e6 1e6

During the simulation you can assign a different atom type to a group of atoms

set region halfbed type 2

Cheers,
Moritz

PS: I tried that with version 1.5.0 and it worked just fine.