[Partially solved] Set a custom material solely to ONE node

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EkaitzEsteban
Posts: 98
Joined: Wed Sep 12, 2018 1:31 pm

[Partially solved] Set a custom material solely to ONE node

Postby EkaitzEsteban » Sun Sep 23, 2018 9:52 am

Hello,

I am exploring and editing manually the .inp file for performing different frequency analyses.

However, I have a problem when defining different materials.

How can I define more than one material set?

It is possible to define a material set SOLELY to ONE node?

best regards,
Ekaitz.
Last edited by EkaitzEsteban on Mon Sep 24, 2018 1:28 pm, edited 1 time in total.
Jee-Bee
Posts: 1866
Joined: Tue Jun 16, 2015 10:32 am
Location: Netherlands

Re: [Help] Set a custom material solely to ONE node

Postby Jee-Bee » Sun Sep 23, 2018 12:49 pm

I think this is more a fem related issue than a material related issue. However don't know why you need a singe node as another material...

The only way to archive this i thing would be add a point to the model and mark the model as one material and the other part(s) as their own material(s). I think this option would be great also for solo points. In this way can make the single node rigid and or make springs between the the point and the object(s).
For me that would be a great improvement!
EkaitzEsteban
Posts: 98
Joined: Wed Sep 12, 2018 1:31 pm

Re: [Help] Set a custom material solely to ONE node

Postby EkaitzEsteban » Mon Sep 24, 2018 2:31 am

Jee-Bee wrote:
Sun Sep 23, 2018 12:49 pm
I think this is more a fem related issue than a material related issue. However don't know why you need a singe node as another material...

The only way to archive this i thing would be add a point to the model and mark the model as one material and the other part(s) as their own material(s). I think this option would be great also for solo points. In this way can make the single node rigid and or make springs between the the point and the object(s).
For me that would be a great improvement!
Thank you Jee Bee. It is true, maybe is FEM related problem. (It is possible to remove the post to FEM?)
I want to see the differences of stiffness and mass very locally when performing a frequency analysis. This is the aim of changing the material of one single node.

Thank you for your solution but I am not sure... I guess that adding a new point should add not only the mass and stiffness in that point, but also the material of whole part... The characteristics of two materials should be added in that point.
chrisb
Posts: 16351
Joined: Tue Mar 17, 2015 9:14 am

Re: [Help] Set a custom material solely to ONE node

Postby chrisb » Mon Sep 24, 2018 6:10 am

(Moved to FEM)
EkaitzEsteban
Posts: 98
Joined: Wed Sep 12, 2018 1:31 pm

Re: [Help] Set a custom material solely to ONE node

Postby EkaitzEsteban » Mon Sep 24, 2018 6:48 am

chrisb wrote:
Mon Sep 24, 2018 6:10 am
(Moved to FEM)
Thank you.
Jee-Bee
Posts: 1866
Joined: Tue Jun 16, 2015 10:32 am
Location: Netherlands

Re: [Help] Set a custom material solely to ONE node

Postby Jee-Bee » Mon Sep 24, 2018 9:17 am

EkaitzEsteban wrote:
Mon Sep 24, 2018 2:31 am
I guess that adding a new point should add not only the mass and stiffness in that point, but also the material of whole part... The characteristics of two materials should be added in that point.
No clue what you meant... here. can you explain?
fandaL
Posts: 327
Joined: Thu Jul 24, 2014 8:29 am

Re: [Help] Set a custom material solely to ONE node

Postby fandaL » Mon Sep 24, 2018 1:11 pm

EkaitzEsteban wrote:
Sun Sep 23, 2018 9:52 am
It is possible to define a material set SOLELY to ONE node?
Usually material properties are defined on elements, but in CalculiX there is a special element type for defining mass at node. Look to the manual on the element types and *MASS card
http://www.feacluster.com/CalculiX/ccx_ ... ode68.html
http://www.feacluster.com/CalculiX/ccx_ ... de272.html
e.g.

Code: Select all

** define mass element number 2000 at node number 4000 and put it to the element set EM
*ELEMENT, TYPE=MASS, ELSET=EM
2000, 4000

** assign mass properties (mass of 0.1 t if you work in mm and have density in t/mmˆ3) to all elements in the EM element set. 
*MASS, ELSET=EM
0.1
EkaitzEsteban
Posts: 98
Joined: Wed Sep 12, 2018 1:31 pm

Re: [Help] Set a custom material solely to ONE node

Postby EkaitzEsteban » Mon Sep 24, 2018 1:21 pm

fandaL wrote:
Mon Sep 24, 2018 1:11 pm
EkaitzEsteban wrote:
Sun Sep 23, 2018 9:52 am
It is possible to define a material set SOLELY to ONE node?
Usually material properties are defined on elements, but in CalculiX there is a special element type for defining mass at node. Look to the manual on the element types and *MASS card
http://www.feacluster.com/CalculiX/ccx_ ... ode68.html
http://www.feacluster.com/CalculiX/ccx_ ... de272.html
e.g.

Code: Select all

** define mass element number 2000 at node number 4000 and put it to the element set EM
*ELEMENT, TYPE=MASS, ELSET=EM
2000, 4000

** assign mass properties (mass of 0.1 t if you work in mm and have density in t/mmˆ3) to all elements in the EM element set. 
*MASS, ELSET=EM
0.1
I agree that material properties are defined on elements. *MASS card can be a way to achieve what I am doing...

Thank you faldaL.