PyLith behavior when using a thin layer inside a larger domain

PyLith
1

Hi Brad,

I am trying to understand the behavior of PyLith for a simple 2.5D model with gravity. In this set up, the model is 10 km x 2 km x 100m with an inclusion of an horizontal layer that is 50m thick. See the sketch below.

All sides, except the top boundary, have roller boundary conditions and I am using gravitational body forces. All materials are elastic.

I was expecting the model to show an uniform displacement in the Z direction, but instead what I find is that the thin layer shows a displacement that is much larger than the surrounding. See figure below with the results.

Could you comment on what could be causing this issue ? Do you think that this is correct ?

Below is a zip folder with the set up (.cfg file, .jason file and mesh journal file ) that can be used to reproduce the behavior.

Thanks,
Josimar

Model_Setup
Model_Setup1612×992 24.9 KB

Model_Results
Model_Results2208×1086 53.3 KB

PyLith_ProblemSetup.zip (347.3 KB)

PyLith version details:

PyLith
Release v2.2.1

PETSc
Configured on 2017-08-03 14:01:44 -0500, GIT branch: branch-not-available, revision: v3.7.6-4826-gd686aaf

Spatialdata
Release v1.9.10

MPI standard: 3.0, implementation: MPICH, version: 3.1.3
HDF5 version: 1.8.11
NetCDF version: 4.4.1.1
Proj version: 480

2

My initial guess is that your inclusion is not attached on all sides to the surrounding mesh. This can happen if you don’t merge all surfaces. I will try to look deeper into this later today or tomorrow.

1 Like
3

Hi Brad,

Thank you very much for the suggestion. I fixed the problem by using the following commands after the mesh was created:

imprint all
merge all

Thanks,
Josimar

4

You should use these commands at the end of the geometry creation, before you create the mesh.