# Adding a dynamic force **URL:** \ **Category:** Uncategorized\ **Created:** [November 10, 2022, 4:19pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336 "2022-11-10T16:19:03Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 10, 2022, 4:19pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/1 "2022-11-10T16:19:03Z")
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 > STEP 1 - GRAVITY LOAD > \*STATIC > 0, 1 > \*DLOAD > 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? ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 10, 2022, 5:53pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/2 "2022-11-10T17:53:27Z")
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`. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 11, 2022, 8:57pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/3 "2022-11-11T20:57:20Z")
Yeah I mean time-dependent force. Please, can you correct my inp file? ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 11, 2022, 9:48pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/4 "2022-11-11T21:48:58Z")
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. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 12, 2022, 11:33pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/6 "2022-11-12T23:33:58Z")
Thank’s a lot. I will try all your instructions and see if it work correctly. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 14, 2022, 6:06pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/7 "2022-11-14T18:06:24Z")
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 > distributed facial loads: 0 > distributed volumetric loads: 1 > concentrated loads: 0 > 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 > \*WARNING reading \*AMPLITUDE. Card image: > \*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: > STEP1-GRAVITYLOAD > STEP 1 > Static analysis was selected > Decascading the MPC’s > 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? ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 14, 2022, 8:29pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/8 "2022-11-14T20:29:12Z")
> [@Fatiha\_GHOUINI](#): > > \*WARNING in calinput. Card image cannot be interpreted: > \*WARNING reading the input file. Card image: > STEP2 > STEP 2 Remove those lines with description after \*STEP or add \*\* to turn them into comments. > [@Fatiha\_GHOUINI](#): > > \*ERROR in CalculiX: in nonlinear calculations > energy output must be selected in the first step Add this to the first step: \*EL FILE ENER ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 16, 2022, 11:11am UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/9 "2022-11-16T11:11:01Z")
I followed your instructions and I had the following warning and error > \*WARNING reading \*AMPLITUDE: parameter not recognized: > INPUT=amplitude.inp > \*WARNING reading \*AMPLITUDE. Card image: > \*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 > \*\*STEP 1 - GRAVITY LOAD > \*STATIC > 0, 1 > \*DLOAD > 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, ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 16, 2022, 12:02pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/10 "2022-11-16T12:02:04Z")
> [@Fatiha\_GHOUINI](#): > > \*BOUNDARY > Nall, 3, 10 This means that you are trying to constrain DOFs 3 to 10 while 6 is max available for mechanical calculations. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 17, 2022, 5:56pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/11 "2022-11-17T17:56:52Z")
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. ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 17, 2022, 10:20pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/12 "2022-11-17T22:20:16Z")
Check all the definitions that use node sets as input (like boundary conditions). Make sure that proper node set names are used. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 18, 2022, 5:58pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/13 "2022-11-18T17:58:46Z")
all is right I don’t know that’s the wrong. ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 18, 2022, 6:59pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/14 "2022-11-18T18:59:08Z")
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. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 20, 2022, 11:32am UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/15 "2022-11-20T11:32:47Z")
the following link has all my files. [https://drive.google.com/drive/folders/1PmojUpqwCTtNM1qClEgWdAOAe00v6hDf?usp=share\_link](https://drive.google.com/drive/folders/1PmojUpqwCTtNM1qClEgWdAOAe00v6hDf?usp=share_link) ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [November 20, 2022, 5:18pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/16 "2022-11-20T17:18:32Z")
It will work if you paste the contents of the include files to the main input file. Then just add ENER to \*EL FILE and it will run correctly. ---
**Author:** ![Fatiha\_GHOUINI](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/fatiha_ghouini/32/1138_2.png) [@Fatiha\_GHOUINI](https://calculix.discourse.group/u/Fatiha_GHOUINI)\ **Post date:** [November 23, 2022, 2:52pm UTC](https://calculix.discourse.group/t/adding-a-dynamic-force/1336/17 "2022-11-23T14:52:41Z")
Now I have a new error, can you help me to solve it please? > 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