Buckling analysis

narasimhamurthy

Hi,

 

I am trying to do buckling analysis with 100 N compression load and 1800 mm length model.

 

The model has Foam and HLP material and both material components contacted with Freeze contact.

 

but results are not good, showing Lanczos solver warnnings.

 

 

 Lanczos solver warnnings for eigenvalue subcase 2.
 - At some point in the process, an inconsistent inertial count was found.
   This implies that some of the calculated frequencies may be inaccurate,
   especially the duplicated frequencies. To avoid this, specify both bounds
   and keep the bound away from the currently calculated frequencies.

     *** warning *** the rayleigh quotient 
     x'kx / x' kd x for the      1-th eigenvector 
     does not match the computed eigenvalue
          lambda (     1) :     4.60386096283964D-01
          x' k x          :     9.99991771675112D-01
          x' kd x         :     6.74831158344970D-02
          discrepancy     :     9.68931456093804D-01

     eigenvalues and eigenvector residuals
     -------------------------------------

               eigenvalues      norm of     estimated
             (radian/sec)**2    residual    accuracy
             ---------------    --------   ---------

          4.60386096283964D-01  1.2687D-01  1.2687D-01
  
 (Scratch disk space usage for starting iteration = 227816 MB)

Subcase:       1
--------------------------------------------------------------------------
 Label     x-force    y-force    z-force   x-moment   y-moment   z-moment 
--------------------------------------------------------------------------
Sum-App.  0.000E+00  0.000E+00 -1.000E+02 -3.353E+04  4.001E+04  0.000E+00
Sum-SPCF  5.472E-06  5.587E-05  1.000E+02  3.353E+04 -4.001E+04  2.051E-02
--------------------------------------------------------------------------

 

 

 

Please give suggestion, how to solve this warning?

 

Thanks and regards

Narasimhamurthy

Altair Forum User

Hi,

 

Can you check if there are any free nodes?

 

Also check the constraints.

narasimhamurthy

Hi,

 

There is no free nodes.

 

Assigned one All DOF constrained through RBE2.

Altair Forum User

Can you share the model file?

 

Use this LINK to share the model.

narasimhamurthy

Please check drop box, i have sent .fem file.

Altair Forum User

@narasimhamurthy

 

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