Negative cross-coupling spring in ABAQUS

[TEIF-RO]

Hello everyone.
I will like to add a cross spring stiffness in my abaqus model. The value is KLR=-3.08E8. I have already consider the negative sign in the analytical model with no problem. Now my question is:
How to add spring with negative stiffness in abaqus since abaqus doesn't accept the (-) sign ?
Regards

 

[FEA way]

Try specifying that negative stiffness directly in the input file/keyword editor instead of using Abaqus/CAE. Many things that can't be achieved in CAE are possible through .inp file.

 

[TEIF-RO]

@FEA WAY.I opened the .inp file and added the negative value then save it. but when I run the model an re-opened the .inp file, the added value was no more there plus my results remained unchanged.
So it did nor work

 

[FEA way]

Did you open this .inp file in CAE after the changes ? If yes then probably these changes were removed by CAE. It often happens when something not supported by CAE is written in the imported input file.

Also did you try with nonlinear spring ?

 

[TEIF-RO]

1-I OPENED THE .inp file generated by my model using Textpad.

2-I modified and saved then I imported it in CAE and ran it.

my spring is not non linear its a cross-coupled spring(In fact it's a cross-coupling stiffness KLR for slender piles in an homogeneous soil)

 

[FEA way]

That’s why it got deleted - importong to CAE causes that. Modify the input file and run it through command line without using CAE.

 

[TEIF-RO]

Please can you give the steps to run it through commands?
I'm new in this
Thanks

 

[FEA way]

Sure. Just run the command line where input file is located (Shift + RMB and choose „Open command window here” to do it) and type:

abqXXXX j=input_file_name interactive cpus=number_of_available_processors

where XXXX is Abaqus version (for example 2017, 2018 or 2019)

 

[TEIF-RO]

THANKS
Its shows me ''Open PowerShell window here'' INSTEAD

 

[FEA way]

You may have to activate „Open command window here” option first:

https://m.windowscentral.com/add-open-command-window-here-back-context-menu-windows-10

Another reason is that it can’t be done in some restricted locations such as Desktop or Documents.

 

[TEIF-RO]

I activated. and thanks.