
Re: Symmetry Restraints
Anthony Botting Jan 15, 2014 2:43 PM (in response to Ben Morrissey)Assuming the body is not sliced in half parallel to the plane in which it resides, it should be 750 each gripped surface (assumes quartersymmetry). After a run, check the reactions on the restrained (symmetry) faces and they should be 1500 each orthogonal direction. Hope that helps.

Re: Symmetry Restraints
Mike Pogue Jan 15, 2014 3:19 PM (in response to Ben Morrissey)I disagree with Anthony. If I'm understanding everything correctly, the test machine pulled 3000 N vertically and 3000 N pulling horizontally. This means there was 3000 pulling up, 3000 pulling down, 3000 pulling left, and 3000 pulling right. The force to the left does not add to the force on the right. 3000 left + 3000 right = 3000 static. If you use 1/4 symmetry, you should have 1500 N pulling on each half surface. You could also take this model to 1/8 symmetry by cutting it diagonally. It would still be 1500 N on the remaining half surface.

Re: Symmetry Restraints
Ben Morrissey Jan 15, 2014 3:31 PM (in response to Ben Morrissey)Sorry I should clarify, it's a total of 3000N on each axis, so average of 1500 being pulled on each. Also it's 1/8 model as I halved it through its thickness aswell as quartering it

Re: Symmetry Restraints
Mike Pogue Jan 15, 2014 4:41 PM (in response to Ben Morrissey)Whoops. I missed the split the last way. Anthony is right and I am wrong. So, If you have 1/4 the top surface left, then it needs 750 N.


Re: Symmetry Restraints
Anthony Botting Jan 15, 2014 3:43 PM (in response to Ben Morrissey)A quick test is to query the reactions and it will tell you the loads along each axis.

Re: Symmetry Restraints
Jared Conway Jan 15, 2014 4:59 PM (in response to Anthony Botting)cross ref to original posting: https://forum.solidworks.com/thread/76609?tstart=0
1/4 symmetry in each direction = 750
use reaction forces to check


Re: Symmetry Restraints
Ben Morrissey Jan 15, 2014 5:01 PM (in response to Ben Morrissey)What about for 1/8, as I've split down thickness also

Re: Symmetry Restraints
Jared Conway Jan 15, 2014 5:02 PM (in response to Ben Morrissey)you're using an 1/8th symmetry model
but in one direction you really only have 1/4 symmetry.
might be worth drawing out the progression to just make it make sense

Re: Symmetry Restraints
Mike Pogue Jan 15, 2014 8:06 PM (in response to Ben Morrissey)The bottom line is keep the pressure on the loaded surfaces constant. So the load you should apply = 3000 N * (the remaining fraction of the loaded surface). If half the surface is left, put 1500. If 1/4 is left, put 750. You don't have to worry about symmetries and such, you can measure it directly .

Re: Symmetry Restraints
Jared Conway Jan 15, 2014 8:19 PM (in response to Mike Pogue)thats a really good way to think of it

