How to write inp for constraint

1

Hello,

I have a simulation constraint defined as follows:
1.The temperature of the bottom face is set to 353K.
2.The initial temperature for all faces is 323K.
3.Heat flux and ambient temperature are specified as 20W/m^2K and 323K, respectively.
4.The thermal expansion coefficients -0.0032204, -0.0014441, -0.0134487.
5.The material being used is steel with a Young’s Modulus of 200 GPa and a Poisson’s ratio of 0.3.

Could someone explain how to create the inp for this constraint or how to give this constraint in the below inp?

** Nodes +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Node
1, 0.00000000E+000, 1.00000000E+001, 0.00000000E+000
2, 0.00000000E+000, 0.00000000E+000, 0.00000000E+000
3, 0.00000000E+000, 0.00000000E+000, 1.00000000E+001
4, 0.00000000E+000, 1.00000000E+001, 1.00000000E+001
5, 1.00000000E+001, 0.00000000E+000, 0.00000000E+000
6, 1.00000000E+001, 1.00000000E+001, 0.00000000E+000
7, 1.00000000E+001, 0.00000000E+000, 1.00000000E+001
8, 1.00000000E+001, 1.00000000E+001, 1.00000000E+001
9, 0.00000000E+000, 0.00000000E+000, 5.00000000E+000
10, 0.00000000E+000, 5.00000000E+000, 1.00000000E+001
11, 0.00000000E+000, 5.00000000E+000, 5.00000000E+000
12, 0.00000000E+000, 1.00000000E+001, 5.00000000E+000
13, 0.00000000E+000, 5.00000000E+000, 0.00000000E+000
14, 1.00000000E+001, 5.00000000E+000, 0.00000000E+000
15, 1.00000000E+001, 1.00000000E+001, 5.00000000E+000
16, 1.00000000E+001, 5.00000000E+000, 5.00000000E+000
17, 1.00000000E+001, 0.00000000E+000, 5.00000000E+000
18, 1.00000000E+001, 5.00000000E+000, 1.00000000E+001
19, 5.00000000E+000, 0.00000000E+000, 0.00000000E+000
20, 5.00000000E+000, 0.00000000E+000, 5.00000000E+000
21, 5.00000000E+000, 0.00000000E+000, 1.00000000E+001
22, 5.00000000E+000, 1.00000000E+001, 0.00000000E+000
23, 5.00000000E+000, 1.00000000E+001, 5.00000000E+000
24, 5.00000000E+000, 1.00000000E+001, 1.00000000E+001
25, 5.00000000E+000, 5.00000000E+000, 0.00000000E+000
26, 5.00000000E+000, 5.00000000E+000, 1.00000000E+001
27, 5.00000000E+000, 5.00000000E+000, 5.00000000E+000
**
** Elements ++++++++++++++++++++++++++++++++++++++++++++++++
**
*Element, Type=C3D10, Elset=Solid_part-2
1, 4, 2, 5, 3, 11, 19, 27, 10, 9, 20
2, 4, 6, 5, 1, 23, 14, 27, 12, 22, 25
3, 5, 8, 4, 7, 16, 24, 27, 17, 18, 26
4, 5, 7, 4, 3, 17, 26, 27, 20, 21, 10
5, 4, 5, 2, 1, 27, 19, 11, 12, 25, 13
6, 4, 5, 6, 8, 27, 14, 23, 24, 16, 15
**
** Node sets +++++++++++++++++++++++++++++++++++++++++++++++
**
*Nset, Nset=FixedSet
1, 2, 5, 6, 13, 14, 19, 22, 25

** Steps +++++++++++++++++++++++++++++++++++++++++++++++++++
**
**
** Step-1 ++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Step
*Static
**
** Output frequency ++++++++++++++++++++++++++++++++++++++++
**
*Output, Frequency=1
**
** Boundary conditions +++++++++++++++++++++++++++++++++++++
**
*Boundary, op=New
** Name: Fixed-1
*Boundary
FixedSet, 1, 6, 0
**
** Loads +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Cload, op=New
*Dload, op=New
**
** Defined fields ++++++++++++++++++++++++++++++++++++++++++
**
**
** History outputs +++++++++++++++++++++++++++++++++++++++++
**
**
** Field outputs +++++++++++++++++++++++++++++++++++++++++++
**
*Node file
RF, U
*El file
S, E
**
** End step ++++++++++++++++++++++++++++++++++++++++++++++++
**
*End step

Regards,
Bhavita

2

Haven’t we discussed it already ? Assistance Needed with CalculiX Input File Warnings and Errors - #5 by Bhavita

What’s the problem now ?

I would just add that you need a thermo-mechanical step, not *STATIC but you had *FILM and other keywords in the input file in that previous thread.

3

Quick answer:

  1. *BOUNDARY with DOF 11 which is temperature for thermal analysis. This might not be right for coupled thermomechanical though.
  2. *INITIAL CONDITIONS,TYPE=TEMPERATURE. Again, for thermal, not sure about thermomechanical.
  3. *FILM for convection with ambient temperature. I guess you mean heat transfer coefficient (film coefficient) rather than heat flux (that would be *DFLUX).
  4. *EXPANSION under the *MATERIAL card.
  5. *ELASTIC under the *MATERIAL card.

Beware that 1. and 2. are in conflict. Even if you have a different initial temperature for the bottom face or quickly change its temperature after t=0, it’s kind of unphysical and will likely cause strange looking temperatures in that area until it settles down.

4

when trying to give
*Boundary
Part-1, 11, 323.0
getting this error as shown in figure

MicrosoftTeams-image (2)
MicrosoftTeams-image (2)711×428 8.17 KB

5

Try:

*Boundary
Part-1, 11, 11, 323.0
1 Like
6

You should try reading the manual as you try to set up the simulation. For example, page 405 tells you how to use the boundary card:

• Node number or node set label
• First degree of freedom constrained
• Last degree of freedom constrained. This field may be left blank if only
one degree of freedom is constrained.
• Actual magnitude of the prescribed displacement