Why my modal frequency are same?

- March 28, 2024 at 1:01 pm
  
  Rajkumar Saha
  Subscriber
  
  Hey Guys!
  I have encountered one trouble while trying to solve this model. When I run my modal analysis I am getting same modal frequency value.
  Can anyone suggest why I am getting that.
  3.9008
  4.5441
  4.5441
  4.5441
  4.5441
  4.5441
  4.5441
  4.5441
  4.5441
  4.9365
  4.9849
  4.9949
  5.1824
  6.2385
  6.3399
  6.3432
  6.3446
  6.3484
  6.3549
  6.3579
  This are my first 20 frequency value.
- March 28, 2024 at 10:39 pm
  
  peteroznewman
  Subscriber
  
  It looks like your structure has 4 almost identical trusses along the top. In the mode shown, the trusses are vibrating: down,up,up,down. That is one of 16 modes starting with: down, down, down, down and ending with: up, up, up, up. All 16 modes have similar frequencies. This is normal and is no trouble.