## General Mechanical

#### Measure angle of rotation in ANSYS.

• Faryal
Subscriber

I have a structure i have applied a moment. I need to find the angle of rotation at the outer most surface. Is it the right method and formulae i am using?

• peteroznewman
Subscriber

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• Faryal
Subscriber

ok so my method is right to find the rotation angle at the outer ring?

• peteroznewman
Subscriber

Looking at the equation under the title My calculation, you have defined a quantity sigma equals R * delta_theta.

In this equation, sigma is the length of the circumferential path traveled by a point on a circle of radius R for a rigid body rotation of delta_theta.

That equation is correct. Then you rearrange the equation to compute delta_theta from sigma/R.

This is also correct assuming sigma is measured using the definition above.

But how did you extract sigma from the FE results?

It would be wrong to request the Total Deformation of a node on the edge of a circle.  For example, say you had a circular rod with a diameter of 10 mm. Now twist that rod 180 degrees using a Remote Point (Behavior Rigid).  A node on the edge has moved around the circle to the opposite side of the circle, but the Total Deformation result shows 10 mm, even though the path it traveled was pi*5 = 15.7 mm in length. If you twisted the rod 360 degrees, the Total Deformation result for that node would now show 0 mm though it had traveled 31.4 mm.

You show a Remote Point and a Flexible Rotation Probe. That will correctly measure the rotation if used appropriately.

• Faryal
Subscriber

Ok I am finding the rotation angle for some moments. But in the parametrization when i update the design points it doesnt give me rotation angle rather it gives some error due to remote points. Because i am measuring rotation angle using remote points.

What should i do?

• peteroznewman
Subscriber

Please show a screen snapshot of the error.

• Faryal
Subscriber