High stress values outside of natural frequencies

rebel
rebel Altair Community Member
edited October 2020 in Community Q&A

Hello,

In Optistruct frequency response modal analysis, I am getting very high stress peaks outside of the natural frequencies. For example, I am applying same amount of acceleration from 1 to 100 Hz. According to the modal analysis, system has natural frequencies at 11.4 , 14.0 , 16.7 , 27.08 Hz. But when I investigate stress vs. frequency, I obtain the highest stress values at 22.6 Hz with much higher than the ones at natural frequencies. What can be wrong here?

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Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited September 2019

    Its not necessary that you would get peak stresses based on natural frequencies.Can you please share some more information related to inputs defined?(.fem & .out file)

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