flowglow
Mechanical
- Apr 30, 2014
- 14
Hello everyone!
I am doing a nonlinear simulation of a compression test of a 2D geometry with round inclusions.
Matrix is modeled as hyperelastic material, material of inclusions is chosen to be a lot stiffer then matrix. Geometry is compressed between two analytical rigid horizontal lines. Contact between rigid lines and matrix has Normal Behaviour with Hard Contact pressure-overclosure and Tangential Behaviour with friction of 0.5. Contact between inclusions and the matrix is the same, but friction is equal to 0.9. Compression is imposed by displacement of a top rigid line.
I used Plane Stress triangular elements from standart Abaqus Library (CPS3: A 3-node linear plane stress triangle.)
The task seems to be easy (The geometry and mesh is presented on the first picture), but each time I run calculation, at the first step I have always the same error following by the same warnings:
Excessive distortion at a total of 25 integration points in solid (continuum) elements
Excessive distortion at a total of 3207 integration points in solid (continuum) elements
And after:
Too many attempts made for this increment
So, I started to investigate the problem, and what I found:
1) If I insert only few inclusions in the middle of geometry - calculation runs;
2) If I add any inclusion close to the geometry border - calculation fails on the first step with the above mentioned error;
3a) If I use geometry with all inclusions, but incline the top rigid line (so the contact starts at the corner) - calculation runs
3b) If the slope of inclined rigid line is small - calculation runs, but result is extrusion of the geometry from the area between of two rigid lines (in simple words - geometry flies away).
I am using Abaqus 6.11-2/Standart
Hope someone will help,
Than you in advance
Attachements:
Problem, initial geometry:
Case of a inclined line - resulting geometry:
Case of 3 inclusions - resulting geometry:
I am doing a nonlinear simulation of a compression test of a 2D geometry with round inclusions.
Matrix is modeled as hyperelastic material, material of inclusions is chosen to be a lot stiffer then matrix. Geometry is compressed between two analytical rigid horizontal lines. Contact between rigid lines and matrix has Normal Behaviour with Hard Contact pressure-overclosure and Tangential Behaviour with friction of 0.5. Contact between inclusions and the matrix is the same, but friction is equal to 0.9. Compression is imposed by displacement of a top rigid line.
I used Plane Stress triangular elements from standart Abaqus Library (CPS3: A 3-node linear plane stress triangle.)
The task seems to be easy (The geometry and mesh is presented on the first picture), but each time I run calculation, at the first step I have always the same error following by the same warnings:
Excessive distortion at a total of 25 integration points in solid (continuum) elements
Excessive distortion at a total of 3207 integration points in solid (continuum) elements
And after:
Too many attempts made for this increment
So, I started to investigate the problem, and what I found:
1) If I insert only few inclusions in the middle of geometry - calculation runs;
2) If I add any inclusion close to the geometry border - calculation fails on the first step with the above mentioned error;
3a) If I use geometry with all inclusions, but incline the top rigid line (so the contact starts at the corner) - calculation runs
3b) If the slope of inclined rigid line is small - calculation runs, but result is extrusion of the geometry from the area between of two rigid lines (in simple words - geometry flies away).
I am using Abaqus 6.11-2/Standart
Hope someone will help,
Than you in advance
Attachements:
Problem, initial geometry:
Case of a inclined line - resulting geometry:
Case of 3 inclusions - resulting geometry: