Hello everyone,
I’m new on CalculiX can you please tell me gow can I add a dynamic force for a beam.

*INCLUDE, INPUT=all.msh
*INCLUDE, INPUT=fixed.nam
*SOLID SECTION, Elset=Eall, Material=EL
*MATERIAL, Name=EL
*ELASTIC
5.E7, 0.3
*DENSITY
1420
*BOUNDARY
Nfixed, 1, 3
*AMPLITUDE, NAME=AMP, INPUT=amplitude.inp
*STEP
*STATIC
0, 1
Eall, GRAV, 9.81, 0, 0, -1
*END STEP
*STEP
STEP 2
*DYNAMIC, DIRECT, EXPLICIT
1.E-01, 1.0
*BOUNDARY
Nfixed, 1, 3
*BOUNDARY,TYPE=ACCELERATION,AMPLITUDE=AMP
Nall, 3, 9.81
*END STEP

This is my inp file can you correct it please?

By dynamic force do you mean time-dependent force ? This can be achieved with `*AMPLITUDE`. But you have to choose the type of load first. For concentrated force use `*CLOAD`.

Yeah I mean time-dependent force.
Please, can you correct my inp file?

Amplitude is already present and used for acceleration boundary condition in that input file. If you want to use it for concentrated force instead, you have to replace *BOUNDARY with *CLOAD. But the rest is up to you - where the force will be applied, in which direction and with what magnitude (multiplied by the amplitude for a given time). You also have to define the amplitude in a tabular form. In the attached input deck its definition is contained in a separate file.

1 Like

Thank’s a lot.
I will try all your instructions and see if it work correctly.

When I try running my inp file i had the following errors

You are using an executable made on So 31. Jul 13:26:31 CEST 2016
The numbers below are estimated upper bounds
number of:
nodes: 126
elements: 40
one-dimensional elements: 0
two-dimensional elements: 0
integration points per element: 27
degrees of freedom per node: 3
layers per element: 1
single point constraints: 18
multiple point constraints: 1
terms in all multiple point constraints: 1
tie constraints: 0
dependent nodes tied by cyclic constraints: 0
dependent nodes in pre-tension constraints: 0
sets: 3
terms in all sets: 298
materials: 1
constants per material and temperature: 2
temperature points per material: 1
plastic data points per material: 0
orientations: 0
amplitudes: 3
data points in all amplitudes: 2
print requests: 0
transformations: 0
property cards: 0
*WARNING reading *AMPLITUDE: parameter not recognized:
INPUT=amplitude.inp
*AMPLITUDE,NAME=AMP,INPUT=amplitude.inp
*WARNING reading *AMPLITUDE: *AMPLITUDE definition AMP
has no data points
*WARNING in calinput. Card image cannot be interpreted:
*WARNING reading the input file. Card image:
STEP 1
Static analysis was selected
Determining the structure of the matrix:
number of equations
360
number of nonzero lower triangular matrix elements
7128
Using up to 1 cpu(s) for the stress calculation.
Using up to 1 cpu(s) for the symmetric stiffness/mass contributions.
Factoring the system of equations using the symmetric spooles solver
Using up to 1 cpu(s) for spooles.
Using up to 1 cpu(s) for the stress calculation.
*WARNING in calinput. Card image cannot be interpreted:
*WARNING reading the input file. Card image:
STEP2
STEP 2
Dynamic analysis was selected
Newton-Raphson iterative procedure is active
*ERROR in CalculiX: in nonlinear calculations
energy output must be selected in the first step

can you help me to solve error?

Remove those lines with description after *STEP or add ** to turn them into comments.

Add this to the first step:

*EL FILE
ENER

I followed your instructions and I had the following warning and error

*WARNING reading *AMPLITUDE: parameter not recognized:
INPUT=amplitude.inp
*AMPLITUDE,NAME=AMP,INPUT=amplitude.inp
*WARNING reading *AMPLITUDE: *AMPLITUDE definition AMP
has no data points
*ERROR in bounadd: unknown DOF: 7

My inp file is:

*INCLUDE, INPUT=all.msh
*INCLUDE, INPUT=fixed.nam
*SOLID SECTION, Elset=Eall, Material=EL
*MATERIAL, Name=EL
*ELASTIC
5.E7, 0.3
*DENSITY
1420
*BOUNDARY
Nfixed, 1, 3
*BOUNDARY
Nall, 3, 10
*AMPLITUDE, NAME=AMP, INPUT=amplitude.inp
**
*STEP
*STATIC
0, 1
Eall, GRAV, 9.81, 0, 0, -1
*NODE FILE
U
*EL FILE
S, E
*END STEP
**
*STEP, INC=1000000
**STEP 2
*DYNAMIC, ALPHA=0.0, DIRECT
1.E-02, 1.0 , 1.E-10, 1.E-02
*BOUNDARY, TYPE=ACCELERATION, AMPLITUDE=AMP
Nall, 1, 1, 1.0
*BOUNDARY, TYPE=ACCELERATION, AMPLITUDE=AMP
Nall, 2, 2, 0.0
*END STEP

thank you,

This means that you are trying to constrain DOFs 3 to 10 while 6 is max available for mechanical calculations.

Please what’s the meaning of this error and how can I solve it?

*ERROR in noelsets: node set 0.00000000
has not been defined yet

I can finally solved all warnings thank you.

Check all the definitions that use node sets as input (like boundary conditions). Make sure that proper node set names are used.

all is right I don’t know that’s the wrong.

Could you share the whole input file with includes (msh, nam) ? You can use some hosting website like Google Drive, Dropbox or WeTransfer and paste a link here.

the following link has all my files.