# Automotive Applying torque to a tube

1. Sep 6, 2016

### bugatti79

Hi Guys,
I have a simple annulus of radius 25mm and 15mm of length 50mm where i applieD a torque of T=100000Nmm. Its inertia about its main axis is I=124.9 kgmm2.
Therefore i expect the acceleration to be T/I.
Its not clear how to confirm this answer in Msc Adams because when i set simulation time of 0.1 or 1 sec I always get increasing velocity/acceleration.
What am I missing?

Regards
B

2. Sep 6, 2016

### Nidum

If you apply a fixed value torque to an object with a fixed value polar moment of inertia then it will just keep on accelerating forever ?

3. Sep 6, 2016

### bugatti79

Then under what conditions does this Torque =inertia times alpha hold that one typically sees in textbooks?

4. Sep 6, 2016

### Nidum

Nothing wrong with the expression .

What is angular velocity of object after time t ? Assume zero initial velocity .

5. Sep 10, 2016

### CWatters

+1

In practice things like friction, air resistance, strength of materials limit the angular velocity but if you don't model those then the angular velocity is unlimited.

6. Sep 10, 2016

### CWatters

Does the acceleration you get in Msc Adams agree with the calculated value?