Initial velocity around an axis

RAMGANESH

Dear All,

 

How to create the initial velocity around an axis ( angular velocity) with respect to the local co ordinate system ( for example about y axis of LCS ) ?

 

Thanks

RAM

Altair Forum User

Dear Ram,

If frame_ID is not given, the initial velocities are applied with respect to the global coordinate system.

Please review the loads once assigned.

<?xml version="1.0" encoding="UTF-8"?>

gopal_rathore

Hi,

If your are using Hypermesh and making use of boundary conditions in utility manager, a big model file usually gets stuck and hyperworks stop functioning. Thus, I would prefer to go for INVEL_AXIS_Collector in load collector and before that make a frame collector (Go to tools>create cards>frame>fix) for LCS. Then in load collector assign this LCS along with axis and the angular velocity to the set of nodes. 

If using hyper crash, you can go using the above table.

RAMGANESH

Dear  Gopal,

 

In Radioss , i have created the LCS but in load collector where to assign the LCS?

 

Thanks

RAM

<?xml version="1.0" encoding="UTF-8"?>

gopal_rathore

Hi,

I am using Hyperworks 13 and getting the same load collector as attached . Frame ID needs to referenced to the frame collector made.

<?xml version="1.0" encoding="UTF-8"?>

gopal_rathore

Hi,

In your case instead of making a frame collector I think you  need to directly give the node coordinates in the above table itself. O_X. O_Y etc. Which version you are using?

RAMGANESH

Dear Gopal,

 

I found that thing. In Block 110 format it is not coming, But in 120 format it is coming.

 

I had changed there but still the velocity is not applied .i had confirmed that by viewing the first animation file generated by the solver in hyperview.

 

By viewing the angular velocity it shows zero values only but it should show 2 rad/sec .

 

I am trying now to remove the mass added from the rigids as suggested by you.

 

Thanks

RAM

RAMGANESH

Dear All,

 

Still i am not getting the velocity applied .

 

Thanks

RAM

Altair Forum User

Dear Ram,

Make IDROT=1 in /IOFLAG and try running the analysis.Please check the results then.

Analysis>>Control Cards>>IOFlagCard

<?xml version="1.0" encoding="UTF-8"?>

gopal_rathore

Hi,

What is the initial kinetic energy value coming in the .001 out file from there we can cross-check whether the initial velocity is applied or not?

RAMGANESH

Dear George & Gopal,

 

Now i got the expected thing. Thank you very much for your valuable support.

 

Thanks

RAM