[ GiDlist ] General questions about GiD

[Attila]

Hi,

I am presently working on finite-element modelisation of
nanoindentation and I have experienced some problems defining the geometry
and conditions of the physical situation in GiD to create a file to be used
by Tochnog. I was unable to solve these problems using GiD's user manual,
so I would therefore like to ask a few questions.

First, how do the coordinates entered to define a dot when creating a
geometrical figure work ? For instance, when creating a square, I enter the
number of sides for the polygon, then the coordinates for its center, a
normal for the polygon, and a value for the radius. But how is this radius
mesured ? When I create a square centered in (0,0,0) in the x-y plane with
a radius of 10 units, the resulting figure has one of its tips at a height
of 8.5, while it should be at 10. It seems that the coordinates entered
manually in the task bar don't match the ones displayed on the screen with
the axes. Moreover, when I zoom or move an object, the coordinates
displayed on the drawing pad change, and the figure is not anymore
positioned at the same place. Is there a way to fix this ? or how do the
coordinates work in GiD ?

Second, I would like to know how to define the materials of which are
made the layers of the substrate and the diamond tip, more specifically
their elastic modulus (E), yield strenght (Y), density, and so on. How
should I proceed to do this ?

I was also wondering if it is possible to consider the initial stress
in the material, the interactions between the surfaces of the layers (the
fact that they are bonded to each other) and the interactions between the
tip and the top surface (a sliding surface with friction) in the
parametrization of the physical problem.

Moreover, I have only been able to create triangular meshes. Is it
possible to create horizontally aligned rectangular meshes representing the
various layers of the material (the implanted amorphous layer and the
substrate) ? If so, how ?

Finally, I would like to know if it is possible to create a
stress-strain curve to define a material or better, to obtain a
load-displacement curve for the simulation that could be compared to the
experimental curve in order to adjust the values of the parameters to
modelize (in this case, E and Y).

Thanks very much for answering my questions.

Francis Loranger, a new user to GiD and Tochnog

P.-S. : I am using GiD's version 6.1.2 for Linux.


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