rotational acceleration input in Patran 2

[vomi1]

Hello,

I am new to Patran. I need to apply a rotational acceration (1 rad/s^2 in the x direction) in the model. How where can I input in the model. What unit should I input? Thank you very much for your help.

Thiet

 

[coach32]

Hi vomi1

To give you an exact answer, we need to know the solver you will use. And also if it is initial rotational acceleration, or if the acceleration acts during all the calculation.

For the units it should be:
rotational acceleration : [Patran Angular Unit]/([TIME Unit]*[TIME Unit]).
[Patran Angular Unit] is radians.

 

[mburlone]

Hi Vomi1,

Step 1: Create a cylindrical coordinate system at the center of rotation with axis 3 oriented along the rotation axis.

Step 2: Create a spatial field with respect to that coordinate system where the second component (tangential component) = 1*'r ('r is the distance to axis 3 of the coordinate system).

Step 3: Assign an acceleration to the nodes using that field.

 

[vomi1]

Hello all,

Thanks you very much for your repsonds!

MSC Nastran is the solver. I was asked to apply just 1rad/s^2 in the x dir (as for trial run) to a node that connect to the rest of the component by a RBE 2 element. In patran window, I go to Loads/Load BC / Create/Acceleration/Input Data, then under Rot Accel I entered <1,0,0> for 1 rad/s^2 in the x-dir. Am I input the right value? I understood that it should be entered in radians.

Many thanks

Thiet

 

[mburlone]

Hi Thiet,

The method you described will move the component like you want assuming there are no other constraints, however you will not obtain stress or strain values since there is no relative displacement of the nodes in the component.