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# Apply "Transient Initial Condition" to body

Pioneer

Hello,

I want to assign an initial velocity to a whole body not just to Polygon Face in NX9, using the 601,129 Solver.

Let me explain the background: I want to do an impact simulation with a certain velocity. I assigned 1000mm/sek to one of polygone face. Checking the .dat file NX translated it correctly and all the nodes belonging to the polygon face get their velocity in the desired direction. It looks like this:

\$* NX Load and Constraint: TransientInitialCondition(1)
TIC      101      145      1      1000.00
TIC      101      146      1      1000.00
TIC      101      147      1      1000.00

.

.

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But when Nastran (or ADINA) calculates the solution, the resultes show slower velocities than I set up. I found out that it depends on the number of nodes I set the "Transient Initial Condition" to. When I mesh the cube with just one element it works out fine and the cube does 1000mm/sek. But when there are morde nodes inside the cube it wont work. I also tried to pick all 6 faces, but the inner nodes wont be picked and therefore the velocity is just a fraction of the intended one.

One solution could be to pick the whole body, so NX assigns the velocity to all nodes of the cube. But NX won't let me pick bodies, just planes an edges. Another would be to set up a higer velocity to compensate the loss, but that's not really practical. I also thought of the cube to a point using 1D-Elements, but the only connect with edges or faces too.

Any suggestions?

Thank you!

JonkMcCool

3 REPLIES

# Re: Apply "Transient Initial Condition" to body

Siemens Phenom

Not sure why Polygon Body is not available in the filter for the boundary condition - please submit an ER to GTAC asking that polygon body be added to the list.

As a workaround, set the Smart Selector to "Related Nodes", then pick the Polygon Body.

If I do this, all nodes in the body get a TIC applied and the results are uniform and independent of mesh density.

# Re: Apply "Transient Initial Condition" to body

Pioneer

Hello JimB,

thanks, that is a good work around that will also help in other situations, although one has probably to do it manually again if the mesh changes. I remember using "related to" in I-DEAS, even twice in a row, but didn't know where it hid in NX.

I've never done an ER so far. Is there a small "How to" somewhere?

Thanks again

JP

# Re: Apply "Transient Initial Condition" to body

Siemens Phenom

This can be done by contacting GTAC online or by phone

http://www.plm.automation.siemens.com/en_us/support/gtac/