General Mechanical

General Mechanical

Forced Response Mode Superposition Bug

    • Tayyip
      Subscriber

      Hi Everyone, 


      I got a problem about how to apply harmonic post results 'manually' in Ansys Harmonic Response Module. I have fan blade with a tuned structure. And I followed methods which are necessary such as


      -unsteady pressure mapping


      -determining resonance point by inserting a campbell diagram


      -applying aerodamping on structure etc.


      by using APDL commands.


      Yet, I guess there is a BUG (see the attachment) in the harmonic response post module when trying to show results manually such as frequency response. It doesn't work! And I guess this is happening when I use cyclic symmetric structure. It doesn't appear in the full model.


      Any idea how to figure this out?

    • Kai
      Ansys Employee

      Hi Tayyip,


      This is a known limitation in MSUP Harmonic with cyclic symmetry. Setting up cyclic symmetric MSUP Harmonic in WB requires rather involved APDL commands and most post-processing (except for modal analysis) are only available through commands objects. Therefore, you have to use command objects to plot Equivalent Stress and Frequency Response.


       


      Thanks,


      Kai 

    • Tayyip
      Subscriber

      Hi Kai,


      Thanks for your response. So, is there any other way to map unsteady pressure distribution without using APDL commands. Because I have limited knowledge about commands and try to do this manually.


      Thanks,


      Tayyip

    • Tayyip
      Subscriber

      Hi Kai,


      I have one more question;


      Is there any other way to map unsteady pressure distribution without APDL commands ??

    • Kai
      Ansys Employee

      Tayyip,


       


      The key here is that running cyclic symmetric MSUP harmonic requires post-processing with APDL commands, so it is not about how you map pressure distribution.  You can try using Full Harmonic method which will not need APDL commands.


      Thanks,

    • Tayyip
      Subscriber

      Hi Kai,


      Thanks for the answer. I didn't realize that I asked it double times, sorry.


      Have a good day,


      Tayyip

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