Learning Forum

[psansys]

Hi all,

I am given the task of FEA of a rotating shaft. Basically I have a belt driven shaft supported by two bearings on two ends. The structure on which the lower part of the bearing is attached is vibrating (using a rotating eccentric mass whose specs are unknown) and is connected to the ground using a number of strong springs. However, we know the amplitudes in x, y and z directions and frequency of vibration of the structure.

My intention is to find the critical speed of the shaft , and to locate the weak points in the entire assembly.

So far, I tried with a simplified model as attached below:

[1shan]

Hey nPlease check out this link -

. For rotor dynamics it is preferred to add a bearing connection since it takes into account the elastic behavior of the bearing by additional stiffness and damping inputs. You could check the help documentation for additional info on bearing connections Bearings (ansys.com). Also you could simulate the vibrating base by adding sinusoidally varying forces in harmonic analysis. Add force defined by components and set a magnitude and phase for each of the components independently. Let me check about Q5/6 and get back to you.nRegards,nIshan.n/forum/discussion/3978/how-to-access-the-ansys-online-helpn

[psansys]

Thank you so much! I'll check it out!nAbout the force and it's components, I have the lab data of displacement values at a particular sensor location only and not the force as such. So, will using the displacement give equivalent results?.TIA.n

[1shan]

Hey Array,nYes, that would work. You can specify a displacement base excitation. Insert displacement>baseexcitation yes>insert sensor data in a tabular format.nRegards,nIshan.nn