Start a topic
With the exception of Windchill, The PTC Community is on read-only status until April 6 in preparation for moving our community to a new platform. Learn more here
cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Showing results for 
Search instead for 
Did you mean: 

The PTC Community is on temporary read only status in preparation for moving our community to a new platform. Learn more here

Translate the entire conversation x

Mechanism is not moving for 0.5ms duration dynamic analysis

vj-3
2-Explorer

Mechanism is not moving for 0.5ms duration dynamic analysis

Hi,

I am trying to run a dynamic simulation for my assembly. It contains the the lever arm with the pivot at the center of the arm. One end I have mass which generates the force of 25N in one direction. I apply 600N of force on the other end in opposite direction (force curve will start at (0,0) to (0.5ms, 600N)). I have the below setting and it seems like the lever is not rotating. Do we need to change any setting if the duration is very small.

 

image.png

1 REPLY 1
SweetPeasHub
17-Peridot
(To:vj-3)

This should easily be calculated by hand.

You did not mention the lever configuration, but a free mass of 2.5kg with an average force applied of 300N for 0.5ms moves the mass 0.015 mm.

These very tiny movements will at least require significant changes to several Creo settings and may not even work at all.

I am not sure about these helping but here are some suggestions to try:

IN FILE - PREPARE - MODEL PROPERTIES (this is tied to the assembly you are using)

1.  Accuracy (for CAD), make accuracy absolute and small enough to capture the tiny motion. maybe <0.00003 mm  because of 0.015mm / 500 frames

2. Mechanism, make relative tolerance * characteristic length small enough. Likely need relative tolerance like 1E-7 or 1E-8.

 

You may need a configuration file change:

accuracy_lower_bound

 

Also, you can try a model with larger time duration that works (like 1000ms) and gradually decrease the loading time. Adjust parameters above when motion is no longer correct to see if they improve the result. Use hand calculations to verify as you go...

 

 

Announcements



Top Tags