Dequations help

Altair Forum User

Hello Optistruct users,

 

I am attempting to run a topology optimization using dequations as a force constraint. I would like to obtain the reaction forces on a bolt (represented as a CBUSH) and calculate the shear forces on the bolt. The shear forces will be calculated using dequations since we can only obtain reaction forces in DOF 1-6 and shear is needed from both DOF 2 and 3 (in this case). I would then like to use the calculated reaction shear force as a constraint. My trouble is relating the reaction forces to the dequation. How do I reference these forces? I am assuming I will need to reference the node number as well. My other concern is relating the dequation to RESP2. When I try to create a response (using function as my response type) I get the response 'a dequation must be selected and edited'. I am not sure if this is due to my equation not having referenced any forces with my variables or not. Do I need to create my eqation in Hypermath? Being that the equation I need is already a built in funtion as rss I am thinking I do not need to use Hypermath.

 

Also, if there is a better way to establish the same result I am open to suggestions.

 

Thanks,

LP

Altair Forum User

Hi,

 

1) First create a response with type as SPCFORCE.

2) Go to Dequation and create your equation which refers this SPCFORCE in the equation (function)

3) If you have any constants to use, you can use table entities to create cosnstants,

4) Create another response (say F2) with response type as Function and chose the dequation function created here.