three parts of a mesh (3 includes)

[Sesa]

Hello,

I want to create a geometry using three different parts of a mesh. I mean, I create one part of the mesh called Ifiber, other called Imatrix and the last one called Iinterface. I´m introducing them in my input file using combine, include and *nodes *elements as It is explained in the manual.
When I plot the geometry is not the one that I wanted, I think that the problem is that it is not tying the 3 different parts of the mesh but I don´t know why because I´m using tie command.
I´ve attached the input file
Thank you very much.

[Prof. R.L. Taylor]

It is hard to tell what is wrong without all the parts -- also you are using user elements which will make it difficult for us to test.

You do not have to send the user elements if you can describe what the nodal connection should be for each type: that is, are they 2-d quadrilaterals, triangles or what shape?

[Prof. R.L. Taylor]

Also, before putting the tree parts together did you test each part separately to see if each one is correct?

[Prof. R.L. Taylor]

Looking at the file it looks like the *node and *element are after each include.  If each part starts with one
the structure should be

include Imatrix

*node = number of nodes in Imatrix
*element = number of elements in Imatrix

include Ifiber

*node = no in Imatrix + Ifiber
*elem =  no in Imatrix + Ifiber

include Iinterface

you do not need anything after the last "include"

[Yaakov]

You may generate such a composite structure mesh with interface elements in Abaqus (Ansys), then get a feap input file from this .inp file using simple matlab. commands lines. By the way, Abaqus student license contains a limit number of mesh elements ...

Best
Yaakov

[Prof. R.L. Taylor]

There is a command in version 8.5 that should automatically renumber individual parts of a mesh [ones where each part is based
on numbers starting from unity (1)].  Thus, for the problem with three parts the input can be

*auto
include Imatrix
include Ifiber
include Iinterface

This avoids need to know specific values for *nod and *ele

[Sesa]

Hello,

Thanks for your help. I tested each part separately and it Works. I'm using quadrilateral elements and I have tried *auto command and the last include without *nodes and *elements but I have the same problem.
I´ve attached the parts of the mesh

[Yaakov]

Hello,

we may go back to the "first" step.

How do you generate interface elements/ cohesive/adhesive elements mesh (via abaqus or own matlab code)?

for 2d problem, 4 node elements for solid + cohesive

Exampel:

ELEM

1 0 1 1 2 3 4
...
20  0 2 20 21 22 23
...
200 0 3 300 301 302 303

MATE1+ MATE 2 is solid materials, MATE 3 is cohesive

solid element and cohesive elements contain here the same number of nodes.

You may get such a simliar logical .inp file from mesh-solver (e.g. Abaqus)   

E.G.
Step 1:
In Abaqus
*Elset, elset=Set-10, generate
  4897,  10485,      1

Step 2:
In MATLAB/Octave (you can also use Excel/VBA...)
F5 + nn( 4897:10485,3)=10

Step 3:
In FEAP
4897 0 10 ...
...
10485 0 10 ...

I hope that such a strategy can make your work more efficient.

Regards,
Yaakov

[Prof. R.L. Taylor]

Sesa:

I replaced your material properti;es by standard feap solid elements.  I used *auto and feap ver8.5 and it works to produce two disks on the screen.

What version are you using?