How to fix the center of a Gear?

[zeke27]

Hi,

I´m trying to simulate the contact between two gears. Each gear has 60 triangular teeth and all of them are in contact at the same time. I have one external gear and one internal gear. The internal gear is driven by a torque applied at it center. I know that I should fix the center of the gear but I don´t know how!, I mean which command should I use. I´ve been reading the manual and I couldn´t info about my problem.
I´ve started to use this program three weeks ago, so I´m new!

Best wishes.

Ezequiel

 

[johnhors]

I suggest that you attend a training course.

 

[zeke27]

But that is not the answer for my problem.

Do you know how to fix the center of a gear?

 

[rstupplebeen]

Search coupling in the help and this forum.

http://www.eng-tips.com/viewthread.cfm?qid=181922

Rob Stupplebeen

 

[zeke27]

Hi,

Thanks

I want to fix the center of a cylinder and then apply a torsion moment (the only DOF free should be the axis of rotation) to see the rotation.
For doing this, I create a reference point on the axis of rotation and a cylindrical coordinate system. Then I create a Kinematical Coupling Constraint to apply the moment (on the RP).

For fixing the axis of rotation should I apply the BC on the RP o should I create another RP on the axis of rotation and create a Distribution Coupling Constraint to apply the BC ?

I´ve been reading the manual but I have several doubt about it. If anyone could give me some tips about it I would be greatly appreciated.

Thanks in advance!!

 

[rstupplebeen]

The RP that was used for the coupling.

Rob Stupplebeen

 

[zeke27]

This is what I´v done, (I´m analyzing a cylinder to see if it works)

I create the RP and the Kinematic coupling constraint. After pick this RP as a control point I chose the "node region" and I applied a torsional moment in the direccion of the axis of rotation (UR3).

As you said, On the same RP I apply the BC for my model (U1 U2 U3 UR1 UR3)

Doing this I have this error: "Excessive distortion at a total of 90 integration points in solid (continuum) elements"

What I´m doing wrong?

Thanks!

 

[rstupplebeen]

1. Look at the deformed results where the solution gets to. Obvious errors can usually be found

2. Try applying a very small rotation instead of the moment.

Rob Stupplebeen

 

[bassmanjax]

You need to tell us what you've coupled the reference point to? Is it a surface? A set of nodes? You may need some further boundary conditions on the mesh itself.

I would try what Rob suggested above aswell.



Martin Stokes CEng MIMechE

 

[zeke27]

Hi,

I´m sorry for not answer before.

I´ve coupled the reference point to a surface. One RP for the Driver and one RP for the Driven. Both RPs are in the axis of rotation.

For the Driver, I applied the moment (UR3) and the BC(only free UR3) on the RP. For the Driven I applied the BC (fully fixed) on the RP. Both are Kinematic Coupling.

The problem is that I have the stress till the half of the tooth length. After the half length, the value is zero.

Do you know how can I fix it?

Thanks in advace.