Inventor General Discussion

## Inventor General Discussion

Active Member
Posts: 8
Registered: ‎10-05-2012
Message 1 of 15 (840 Views)

# Centrifugal force applied to a pendulum in dynamic simulation

840 Views, 14 Replies
10-05-2012 01:02 AM

Hi guys, i am new here on the forum, but not new with Inventor. Version i work with is 2011. I want to make Inventor calculate for me the force by which the pendulum acts towards the die ring, which is grounded. In my simulation, i defined material properties of all the parts, gravity, motion around vertical axis is set to constant value. It turns nicely. But, i can not set the die ring to be the position limiting factor to my pendulum and i can not make centrifugal force created by rotation to act on the pendulum. I attach picture of model, which i created to test if this works.  Thanks a lot if someone come up with something.

There are a couple different ways to go about it.  The easiest way is to disable the zero deg/s^2 acceleration imposed motion in Revolution:1.  Then you can see the ~63.9 N rolling force between the cylinder and ring.

I also re-constrained the simulation a little bit by removing the zero acceleration imposed motion in Revolution:1, disabled the rolling joint and replaced it with a 2D contact joint between the roller and outer ring.  There you can see the contact (action / reaction) force calculated as ~64 Newtons (assembly attached).

Best regards, -Hugh

*Expert Elite*
Posts: 28,228
Registered: ‎04-20-2006
Message 2 of 15 (825 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

What book are you using to learn Dynamic Simulation?

Can you attach your assembly here?

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Message 3 of 15 (815 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

10-05-2012 04:38 AM in reply to: JDMather

Hi and thank you for the answer. I do have "Up and Running with Autodesk Inventor Simulation 2011" and "Mastering Autodesk Inventor 2010". I attach the assy here.

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Message 4 of 15 (805 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

I don't think either of those books cover Dynamic Simulation (in any detail), I was thinking more of Wasim Younis book http://www.amazon.com

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Message 5 of 15 (791 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

10-05-2012 07:12 AM in reply to: JDMather

It is his book. See attached

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Posts: 28,228
Registered: ‎04-20-2006
Message 6 of 15 (771 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

Yes, but I'm not sure your problem is covered in the book.

If you don't have money to purchase the book or if this is your only real need (to solve this particular problem) you might wait a couple of days and see if someone posts a solution (Fridays are usually slow).

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Autodesk Inventor 2015 Certified Professional
Certified SolidWorks Professional
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Message 7 of 15 (761 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

10-05-2012 09:17 AM in reply to: JDMather

It is not a problem to buy some book, if i know there is an sollution in there. I will look if i can find some other book related to this topic. I am still working on that one and won't stop till i get it right. Will use that more than once.Thanks for answer.

Employee
Posts: 651
Registered: ‎06-07-2007
Message 8 of 15 (747 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

There are a couple different ways to go about it.  The easiest way is to disable the zero deg/s^2 acceleration imposed motion in Revolution:1.  Then you can see the ~63.9 N rolling force between the cylinder and ring.

I also re-constrained the simulation a little bit by removing the zero acceleration imposed motion in Revolution:1, disabled the rolling joint and replaced it with a 2D contact joint between the roller and outer ring.  There you can see the contact (action / reaction) force calculated as ~64 Newtons (assembly attached).

Best regards, -Hugh

Hugh Henderson
Simulation QA Engineer
DLS
Employee
Posts: 651
Registered: ‎06-07-2007
Message 9 of 15 (743 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

10-05-2012 11:05 AM in reply to: henderh

At first when you mentioned pendulum, and had the zero acceleration imposed motion, I thought you wanted to know the reaction force at the center of rotation due to the centrifugal load of the spinning components.  I did a hand calculation and arrived at the same value as DS (158.1 N).  You can view the X or Y component of the Revolution :2 joint and see it matches exactly (images attached)

Warm regards, -Hugh

Hugh Henderson
Simulation QA Engineer
DLS
Active Member
Posts: 8
Registered: ‎10-05-2012
Message 10 of 15 (665 Views)

# Re: Centrifugal force applied to a pendulum in dynamic simulation

10-08-2012 12:42 AM in reply to: henderh

Hi Henderh,

many thanks for your reply. I woul never imagine i could get one like this. Only when i try to open assemblies posted by you, i get Error message saying: "Error in reading RSe stream" so it won't open them. Is there any way to get over this? Another thing, i found out, that you impose motion also on revolution:2 by that little green cross near the joint sign. What motion you impose? Thanks