Rotating loads in frequency response analysis

Bill_22179

Hi, I need to evaluate the response of a structure subject to two dynamic load:

1. 1 motor spining at 1000 RPM - 10 kN amplitude
2. 1 motor spining at 500 rpm - 2 kN amplitude

My questions are:

• Is using FREQi cards setting the frequency range for the overall structural or one particular load (either 1 or 2 in my case)
• In the case of rotating load (this case) what kind of load is used?

Adriano_Koga

FREQi card controls the output of your frequency results. It define both the range and spacing of your frequency output. Too many points might lead to huge files, depending on the model. Too few points might lead to inaccurate results view, over frequency.

for rotating loads, you might want to check Rotor Dynamics.

https://help.altair.com/hwsolvers/os/topics/solvers/os/rotor_dynamics_os_r.htm

https://help.altair.com/hwsolvers/os/topics/chapter_heads/rotor_dynamics_c.htm

https://help.altair.com/hwsolvers/os/topics/solvers/os/rotor_dynamics_unbalance_using_modal_frequency_response_analysis_os_example_r.htm