Hello,
i tried a coupled or uncoupled temperatur-displacement analysis.
It works without NLGEOM perfectly, with NLGEOM the solution is not converging.
Any ideas?
test input:
**
** Heading +++++++++++++++++++++++++++++++++++++++++++++++++
**
*Heading
Hash: dgJUDAxE, Date: 01/18/2024, Unit system: MM_TON_S_C
**
** Nodes +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Node
1, 0.00000000E+000, 0.00000000E+000, 0.00000000E+000
2, 0.00000000E+000, 0.00000000E+000, 2.00000000E+001
3, 0.00000000E+000, 1.00000000E+001, 0.00000000E+000
4, 0.00000000E+000, 1.00000000E+001, 2.00000000E+001
5, 1.00000000E+001, 0.00000000E+000, 0.00000000E+000
6, 1.00000000E+001, 0.00000000E+000, 2.00000000E+001
7, 1.00000000E+001, 1.00000000E+001, 0.00000000E+000
8, 1.00000000E+001, 1.00000000E+001, 2.00000000E+001
9, 0.00000000E+000, 0.00000000E+000, 1.00000000E+001
10, 0.00000000E+000, 1.00000000E+001, 1.00000000E+001
11, 1.00000000E+001, 0.00000000E+000, 1.00000000E+001
12, 1.00000000E+001, 1.00000000E+001, 1.00000000E+001
**
** Elements ++++++++++++++++++++++++++++++++++++++++++++++++
**
*Element, Type=C3D8, Elset=Solid_part-1
1, 10, 9, 1, 3, 12, 11, 5, 7
2, 4, 2, 9, 10, 8, 6, 11, 12
**
** Node sets +++++++++++++++++++++++++++++++++++++++++++++++
**
*Nset, Nset=Internal_Selection-1_Fixed-1
1, 3, 5, 7
*Nset, Nset=Internal-1_Internal_Selection-1_Convective_Film-1
1, 3, 5, 7
*Nset, Nset=Node_Set-2
2, 4, 6, 8, 9, 10, 11, 12
*Nset, Nset=Node_Set-1
1, 3, 5, 7, 9, 10, 11, 12
**
** Element sets ++++++++++++++++++++++++++++++++++++++++++++
**
*Elset, Elset=Internal_Selection-1_Gravity-1
Solid_part-1
*Elset, Elset=Element_Set-1
1
*Elset, Elset=Element_Set-2
2
*Elset, Elset=Internal-1_Internal_Selection-1_Convective_Film-1_S5
1
*Elset, Elset=Internal_Selection-1_Solid_Section-1
Solid_part-1
**
** Surfaces ++++++++++++++++++++++++++++++++++++++++++++++++
**
*Surface, Name=Internal_Selection-1_Convective_Film-1, Type=Element
Internal-1_Internal_Selection-1_Convective_Film-1_S5, S5
**
** Physical constants ++++++++++++++++++++++++++++++++++++++
**
**
** Materials +++++++++++++++++++++++++++++++++++++++++++++++
**
*Material, Name=S235
*Density
7.8E-09
*Elastic
210000, 0.28
*Expansion, Zero=20
1.1E-05
*Conductivity
14
*Specific heat
440000000
**
** Sections ++++++++++++++++++++++++++++++++++++++++++++++++
**
*Solid section, Elset=Internal_Selection-1_Solid_Section-1, Material=S235
**
** Pre-tension sections ++++++++++++++++++++++++++++++++++++
**
**
** Constraints +++++++++++++++++++++++++++++++++++++++++++++
**
**
** Surface interactions ++++++++++++++++++++++++++++++++++++
**
**
** Contact pairs +++++++++++++++++++++++++++++++++++++++++++
**
**
** Amplitudes ++++++++++++++++++++++++++++++++++++++++++++++
**
**
** Initial conditions ++++++++++++++++++++++++++++++++++++++
**
** Name: Temperature-1
*Initial conditions, Type=Temperature
Node_Set-1, 1370
** Name: Temperature-2
*Initial conditions, Type=Temperature
Node_Set-2, 1370
**
** Steps +++++++++++++++++++++++++++++++++++++++++++++++++++
**
**
** Step-1 ++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Step, Nlgeom
*Static
**
** Output frequency ++++++++++++++++++++++++++++++++++++++++
**
*Output, Frequency=1
**
** Boundary conditions +++++++++++++++++++++++++++++++++++++
**
*Boundary, op=New
** Name: Fixed-1
*Boundary
Internal_Selection-1_Fixed-1, 1, 6, 0
**
** Loads +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Cload, op=New
*Dload, op=New
**
** Defined fields ++++++++++++++++++++++++++++++++++++++++++
**
*Temperature, op=New
** Name: Temperature-1
*Temperature
Node_Set-2, 1370
** Name: Temperature-2
*Temperature
Node_Set-2, 1370
**
** History outputs +++++++++++++++++++++++++++++++++++++++++
**
**
** Field outputs +++++++++++++++++++++++++++++++++++++++++++
**
*Node file
RF, U
*El file
S, E, ENER
**
** End step ++++++++++++++++++++++++++++++++++++++++++++++++
**
*End step
**
** Step-2 ++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Step, Inc=100
*Uncoupled temperature-displacement
20, 20, 1E-05, 1E+30
**
** Output frequency ++++++++++++++++++++++++++++++++++++++++
**
*Output, Frequency=1
**
** Boundary conditions +++++++++++++++++++++++++++++++++++++
**
*Boundary, op=New
** Name: Fixed-1
*Boundary
Internal_Selection-1_Fixed-1, 1, 6, 0
**
** Loads +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Cload, op=New
*Dload, op=New
*Cflux, op=New
*Film, op=New
** Name: Convective_Film-1
*Film
Internal-1_Internal_Selection-1_Convective_Film-1_S5, F5, 20, 1
**
** Defined fields ++++++++++++++++++++++++++++++++++++++++++
**
**
** History outputs +++++++++++++++++++++++++++++++++++++++++
**
**
** Field outputs +++++++++++++++++++++++++++++++++++++++++++
**
*Node file
RF, U, NT, RFL
*El file
S, E, ENER
**
** End step ++++++++++++++++++++++++++++++++++++++++++++++++
**
*End step
**
** Step-3 ++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Step, Inc=1000
*Uncoupled temperature-displacement
1E-05, 0.0001, 1E-05, 1E+30
**
** Output frequency ++++++++++++++++++++++++++++++++++++++++
**
*Output, Frequency=1
**
** Boundary conditions +++++++++++++++++++++++++++++++++++++
**
*Boundary, op=New
** Name: Fixed-1
*Boundary
Internal_Selection-1_Fixed-1, 1, 6, 0
** Name: Temperature-1
*Boundary
Node_Set-2, 11, 11, 1370
**
** Loads +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Cload, op=New
*Dload, op=New
*Cflux, op=New
*Film, op=New
** Name: Convective_Film-1
*Film
Internal-1_Internal_Selection-1_Convective_Film-1_S5, F5, 20, 1
**
** Defined fields ++++++++++++++++++++++++++++++++++++++++++
**
**
** History outputs +++++++++++++++++++++++++++++++++++++++++
**
**
** Field outputs +++++++++++++++++++++++++++++++++++++++++++
**
*Node file
RF, U, NT, RFL
*El file
S, E, ENER
**
** End step ++++++++++++++++++++++++++++++++++++++++++++++++
**
*End step
**
** Step-4 ++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Step, Inc=1000
*Uncoupled temperature-displacement
1, 100, 1E-05, 1E+30
**
** Output frequency ++++++++++++++++++++++++++++++++++++++++
**
*Output, Frequency=1
**
** Boundary conditions +++++++++++++++++++++++++++++++++++++
**
*Boundary, op=New
** Name: Fixed-1
*Boundary
Internal_Selection-1_Fixed-1, 1, 6, 0
**
** Loads +++++++++++++++++++++++++++++++++++++++++++++++++++
**
*Cload, op=New
*Dload, op=New
*Cflux, op=New
*Film, op=New
** Name: Convective_Film-1
*Film
Internal-1_Internal_Selection-1_Convective_Film-1_S5, F5, 20, 1
**
** Defined fields ++++++++++++++++++++++++++++++++++++++++++
**
**
** History outputs +++++++++++++++++++++++++++++++++++++++++
**
**
** Field outputs +++++++++++++++++++++++++++++++++++++++++++
**
*Node file
RF, U, NT, RFL
*El file
S, E, ENER
**
** End step ++++++++++++++++++++++++++++++++++++++++++++++++
**
*End step
**
Br,
Frank