1 Reply Latest reply on Jun 21, 2007 2:31 AM by genexxer genexxer

    significance of natural frequency

      dear forum member,
      in dynamic analysis , what are the significance of natural frequency?
      if natural frequency is high, structure weak or strong?
        • significance of natural frequency
          genexxer genexxer
          If the natural frequency is high, generally it means the stiffness is relatively high and the mass is relatively low. The relation f = root(k/m) applies for the first natural frequency. The geometry, Young's modulus, density and boundary conditions are the influencers in the elevation of natural frequency. Strength is a material property and isn't used in the computation of natural frequency, nor is the structure stronger simply due to high natural frequency. I find that using draft quality elements always gives erroneously high natural frequency when bending is in the mode shape. So I avoid them for almost all simulations, except maybe a cylinder in pure axial load.