Learning Forum

[joesymonds]

Hi All,

I'm using multiple bushing joints in a static structural model and would like to select certain stiffness coefficients from the worksheet as parameters, that can then be controlled and varied from the Parameter set tab in Workbench.

In particular the torsional stiffness coefficients about Y and Z. 

This seems like the type of problem that could be resolved with APDL commands, however I have zero experience of using them.

Best regards,

Joe

[joesymonds]

It seems I can add an APDL command under the bushing joint, and you can select ARG1 to 9 as parameters. How do I assign coefficients from the stiffness table shown below to ARG1,2,3 etc. using the APDL command?

[mrife]

Hi Joesymonds

Insert a Command Object to the Static Structural object. Then choose Tools -> Write Input File.  This will write the MAPDL input file for the model in a folder, and file name, of your choosing.  Open the file and search for the word 'Bushing'.  And you will see the commands used to define the bushing.  Then open the Help and go to Help -> Mechanical APDL -> Commands Reference and read up on TB and TBDATA.  You will see that these are the commands that define the stiffness.  And the Bushing Joint is defined by a general joint element type number 184 - look that up in the Elements Reference of the MAPDL Help.  

You will define some stiffness in the GUI, then use the Command Object ARGs to redefine the material properties.

Good luck.
Mike

[joesymonds]

Thank you mrife, your guidance has helped me solve this.

 

tbdata,19,ARG1,0,ARG2 !assigns stiffness properties to Moments about Y and Z

[purichmunlow]

joesymonds mrife How to calculate those coefficients?n

[boris.kamdem]

How to calculate those coefficients for a bushing joint (body - body)?