January 1, 2021 at 2:15 pm
peteroznewman
Subscriber
@bobsik641, @cxquan, nI had one of the simplest models you can imagine, a tube rotating on its axis at a constant velocity. The hourglass energy built up to a huge value and began eroding the elements!n

The material is BRASS from the Explicit Dynamics category of Engineering Data. A solid tube has an initial condition of an Angular Velocity of -36.65 rad/sechttps://us.v-cdn.net/6032193/uploads/ZPD2ADBKHIV0/image.pngThe Remote Displacement ramps a rotation of -1800 degrees in 0.856 shttps://us.v-cdn.net/6032193/uploads/7W04WWY9H1HM/image.pngDoing the math on the angular velocity and the remote displacement, they both come out to be 350 rpm.https://us.v-cdn.net/6032193/uploads/JUQUOYIV8OZ4/image.pngI expect to see a simulation where the solid tube has an uneventful time rotating. Instead the tube erodes away. I understand there will be some stress from the small amount of centripetal force and some Poisson ratio effect, but I didn't expect

is wrong with this model? I know that @MAMIN219 wants to know the answer to this question. https://forum.ansys.com/discussion/21391/thermal-aspects-during-turning-operation#latesthttps://forum.ansys.com/discussion/22283/a-solid-tube-rotating-at-a-constant-350-rpm-erodes-itself-why

Does your model have a Remote Displacement or a Revolute Joint? Both of those caused the problem.nThe workaround was to use a Cylindrical Coordinate System and rotate the tube on its axis using Displacement of the theta DOF in the cylindrical coordinate system.n