Simulation of cutters

[z3158701]

I am trying to simulate a simple problem of finding the reaction force to a set of primary cutters that are being driven by some secondary cutters through a pin connection

My assembly can be found here

https://www.dropbox.com/sh/2zvthm4q7vkh9qo/AABWG57yg3_IrpWPI6J3Zc9wa

The cutters on the left are the primary cutters and the cutters on the right are secondary

I have a fixed support at the blades of the primary cutters because this is the reaction force i wish to check. Also either side of the pin of those primary cutters are fixed

Global contacts set to no penetration

The resultant reaction force is very wrong and much less than expected through game calculations.

Any help would be much appreciated

 

[z3158701]

*The resultant reaction force is very wrong and much less than expected compared to HAND calculations.

 

[shaun8567]

I can't DL your model at work, but I do have a few pointers/questions.

How did you model the pin connection? Did you use CAD geometry? If you did, then I suggest you remove the pin CAD and add in a pin connection within SolidWorks simulation (make sure to allow on axis rotation).

Does a fixed support accurately represent the constraint in your hand calculation? A fixed support prevents all nodal motion over the defined geometry (all translations for solid elements and all translations and rotations for shell and beam elements). It may not be obvious, but you could be introducing reaction loads in your FEM that might not be realistic.

Finally, you need to be careful when using a global contact definition of no penetration, because this can sometimes cause unintended issues. If you're going to use a no penetration condition, then it's best to manually set them up. You might very well be fine using a Bonded or Allow Penetration global definition depending on your geometry and how the system works.

 

[z3158701]

Thank you so much for taking the time to answer Shaun!

It works now!!!

I took on board your advice - switched to global contact of "Allow penetration" and I incorporated local non-penetration contacts in all the necessary areas.

The fixed support at the blades did provide an accurate constraint with results mirroring my hand calculations when i applied the "reaction force" tool at the blades after results were run.

Once again, thanks heaps!!!!!