Learning Forum

[Marius Janisch]

Hey,
I have a big problem, which I am already despairing. To briefly describe my problem. I'm working on a project where I have to look after the construction, what deformations and stresses occur on the components. There are heavy components connected to a beam. These beams are attached to a large wheel. When this wheel rotates, the heavy components are strongly influenced (due to gravity). In addition, centrifugal forces arise due to the rotational speed and rotational acceleration.
So my question is if it is possible to make an analysis where I can see the change in the influences of the forces. So far a harmonic as well as dynamic analysis was not possible (to my knowledge ).

Thanks a lot !!!

[Marius Janisch]

[peteroznewman]

It would help to have a coordinate triad so we can refer to directions. I will assume that the disk is in the X-Y plane and rotates about the Z axis.

Create 3 Static Structural analyses.

The first analysis computes the effect of the angular velocity. Assign a Rotational Velocity using the maximum angular velocity the disk will achieve. (Omega)

The second analysis has a Standard Earth Gravity in the X axis (1G-X)

The third analysis has a Standard Earth Gravity in the Y axis (1G-Y)

Use a Solution Combination where alpha is the angle of rotation to add sine(alpha)*1G-X and cosine(alpha)*1G-Y and add the Omega solution. You might want to create 24 rows of Solution combinations to capture the effect of gravity in 15 degree increments.

[Marius Janisch]

Thank you for your suggestion.

 

I had also thought of this idea, only that it failed because I can only define the gravity at the main axes. Proportionally over cosine and sine is therefore not possible, even if I inserted an additional cylindrical coordinate system. With the solution combinations the area of the phase angle is grayed out. 

[peteroznewman]

Sine and cosine are the scale factors that multiply the 1G loads in the X and Y directions in the Solution Combination table.