[CIG-LONG] stress in particles*vtu to stress in fields*vts

[Walter Landry]

js at cp.dias.ie wrote:
> Hi,
> is it possible to convert the stress / viscosity values given in the
> particles*vtu files to the format of fields*vts.
> 
> I know if I include
>     <struct name="StressField">
>       <param name="Type">StressField</param>
>       <param name="StrainRateField">StrainRateField</param>
>       <param name="Context">context</param>
>       <param name="ConstitutiveMatrix">constitutiveMatrix</param>
>       <param name="Swarm">picIntegrationPoints</param>
>       <param name="Mesh">mesh-linear</param>
>       <param name="IC">stressICs</param>
>     </struct>
> 
> in the input file it gets generated, but this would mean
> having to rerun models and the inclusion of this <struct>
> seems to run very slow on parallel jobs.

You can compute the stress from the viscosity and strain rate.  As is

  stress = 2*viscosity*strainrate

This may give you a slightly different answer from using a
StressField.  StressField computes the stress on the particles and
interpolates to the grid points.  This method interpolates the
viscosity and then computes the stress.

Cheers,
Walter Landry
walter at geodynamics.org