topic Re: Bug with frictionless constraint in Inventor Forum

Bug with frictionless constraint

Anonymous — Fri, 24 Nov 2017 15:11:24 GMT

I have modeled a simpe beam loaded in the middle, hinged at one end and frictionless constraint on a small stub face at the other end. The frictionless contraint generates a reaction FORCE in the frictionless direction... I use inventor 2016

Re: Bug with frictionless constraint

Anonymous — Fri, 24 Nov 2017 16:45:43 GMT

Here's my file

Re: Bug with frictionless constraint

jhackney1972 — Sat, 25 Nov 2017 01:52:03 GMT

A frictionless constrain only prevents motion it does not suppress forces created at the surface or point of application. The bar is pivoting around one end and you applied a frictionless constrain to prevent it from rotating, which is does not, but there still is a force pressing up in the Z axis. It is matched approximately in the reaction forces at the pivot constraint.

I think you have miss interrupted the meaning of a frictionless constraint.

If I placed the bar on the floor in the same fashion with a roller to support the end opposite the pivot and you stood on the middle, there is still a reaction force on the roller end. If you finger was under the roller, it is going to hurt!

Re: Bug with frictionless constraint

Anonymous — Mon, 27 Nov 2017 14:38:24 GMT

Yes but in my case the there is a force created in one of the direction of the frictionless plane, this cannot happen in any kind of analysis unless there is friction. There will be a torque generated, but that should be it, the part should be allowed to move as soon as there is a resultant force in one of the frictionless direction...

Maybe I am using an outdated version, I will try to find how to download the updates

Re: Bug with frictionless constraint

dgreatice — Mon, 27 Nov 2017 15:11:52 GMT

Hi,

it like flat ball at table?, where you table to define contact of frictionless surface.

Re: Bug with frictionless constraint

hosford — Mon, 27 Nov 2017 18:40:50 GMT

If the part is not constrained you cannot get analyses results.

it would squirt sideways under a load.