Topology Optimization of Natural Frequency

- January 13, 2020 at 8:49 am
  
  Pollovr
  Subscriber
  
  Hi,
  
  I'm running a simulation of a small part, I did a modal analysis to get the natural frequencies of the piece, very simple and it gave a correct output, but when trying to do a topological optimization to reduce material while keeping the natural frequency high, the solver gives me the next error:
  
  'Number of natural frequency exceeds number of calculated frequencies'
  
  It's true that it didn't detect any frequency in the first mode (0), but I've changed the objective to optimize the second mode and still, this error pops out. Any reason why it's not working?
  
  Thanks
- January 13, 2020 at 9:27 pm
  
  peteroznewman
  Subscriber
  
  What do you mean by, "it didn't detect any frequency in the first mode (0)"?
  
  Do you mean the first frequency was zero?
  
  That would mean the structure was not fixed to ground.
- January 14, 2020 at 5:44 pm
  
  Pollovr
  Subscriber
  
  It meant that the first mode was 0 Hz, that's because I had frictionless support. I've change it to a fix one instead and still it gives me the same error. I have tried in changing the objectives ("Multiple sets" to "Enable") but still gives me an error, and I just want to maximize the first mode so I believe it should be "disabled".