PDA

View Full Version : real mesh modeling

atmorita
2007-10-10, 21:43
Dear all,

I am new in the field of mechanical simulation of plastics and I would like to ask something.

I need to simulate the deformation of a body that is composed by a rigid square and a mesh in the middle of this square. The polymeric mesh is put in the mold and the rigid square is injected over the mesh.

In order to decrease the computational mesh complexity I supposed that is possible to use a flat plate instead of a mesh model of real plastic mesh.

Has anyone already work in a similar system? Did you analise the mechanical properties of the real plastic mesh?

regards

Augusto

Jorgen
2007-10-12, 14:46
Let's see if I understand, you are trying to model a polymeric mesh (grid) that is overmolded with some other polymer?

If so, you should be able to model that two-phase system if you create a representative finite element model. The tricky part might be the description of the material models of the two materials, and the interface strength.

- Jorgen

atmorita
2007-10-23, 20:00
Dear Jorgen, thank you for your answer.

You mentioned the necessity to have a representative finite element model... my doubt is if it is possible to substitute the complex mesh necessary to model the real polymeric grid by a flat region (lower complexity), but with the same properties (Elastic Modulus, Yield modulus, etc.) of polymeric grid.

Another point is how the materials properties should be analyzed (tensile modulus, yield strength, etc.). The polymeric net (grid) has many holes and because of that it is very difficult to obtain the real transversal area of a tensile test sample.

Is it possible to use the tensile test to measure the properties of the polymeric grid (the force, not the tension) and consider the width and thickness of tensile test sample (and not the real area, which is the sum of area filaments) to calculate the net elastic modulus, net yield strength, etc?

real
+-------+
|#####|
|#####|
+-------+

simulation
+-------+
|..........|
|..........|
+-------+

Regards

Augusto

Jorgen
2007-10-31, 21:35
I see, yes you should be able to approximate the behavior by simplifying the geometry into a flat region. The trick is to determine a good representaion of the response of the "flat" grid. Your suggestion about using a tensile test sounds good.

- Jorgen