SOLUTION
  case eig
    # Compute modes for subsequent use in modal random vibration
    # analysis. 
    eigen
    nmodes=55
    shift=-1e5
  case rms
    modalranvib
    # These options will keep only the 17 modes that are most relative
    # to the ultimate computation of root-mean-squared displacement.
    truncationMethod = displacement
    keepmodes=17   // force modal truncation
End

RANLOADS
  # Single entry power-spectral-density function
  matrix=1 // loads input in lbs.
   load=1  // The PSD is in g^2/Hz.
     nodeset 12 // F = accel * mass
	force=0 1 0   //   = accel * (scale_factor)
	scale 1.00e3  //   = accel * ((1000*.00259)*384.6)
End

Frequency
   freq_step=100
   freq_min=300
   freq_max=1e4
   # Output every node to the frequency file
   BLOCK=all
End

MATRIX-FUNCTION 1
   # Matrix function still needed even for single-input
   # Poser-spectral-density function
   Name=input_Power_Spectral_Density
   symmetry=symmetric
   dimension=1x1
   data 1,1
     real function 1
End

FUNCTION 1
   # This function input, in lbs^2/Hz of the force
   # spectra
   Name='Power_Spectral_Density'
   type=loglog
   data 1.0 1e-8
   data 299 1e-8
   data 300 0.01
   data 2000 0.03
   data 8000 0.03
   data 10000 0.01
   data 10001 1e-8
End

DAMPING
  # Damp every mode by 1% of critical
  gamma=0.01
End

PARAMETERS
 # Convert lbs to slinches on input
 wtmass=0.00259
End

FILE
   geometry_file 'vtube.exo'
End

BOUNDARY
  # Fix translation/rotation DOFs of the input node, other than
  # in the direction force is applied.  This test mimics a single-axis
  # vibration test input
  nodeset 124
  rotx=0 roty=0 rotz=0 x=0 z=0
End

LOADS
End

OUTPUTS
  # Output is root-mean-squared Von Mises stress in each element
  vrms
End

ECHO
  # Also write the stress to the log file in text format
  vrms
End


GDSW
  # Used for Eigen solve, somewhat tighter residual than default
  solver_tol 1e-9
End

BLOCK 101
  # The quad-T element is a quadrilateral shell, that is really just
  # two triangle shells stuck together underneath
  material 101
  quadt
  thickness= 0.200000003E+00
End

BLOCK 102
  # Concentrated mass at a single node.  By scaling the input
  # load PSD by this same Mass value the input BC effectively
  # becomes acceleration rather than force.
  ConMass
    Mass=1000
    Ixx =0
    Ixy =0
    Iyy =0
    Ixz =0
    Iyz =0
    Izz =0
    Offset= 0 0 0
End

Block 1000
   # Structural beam properties.  Cross sectional area, bending moment
   # of inertia (i1, i2), torsional moment of inertia (j).  Orientation
   # tells how the i1 and i2 are aligned in physical space.
   material=1000
   beam2
   area=1
   i1=.1
   i2=.1
   j=.2
   orientation=1 0 .10
end

MATERIAL 101
   density=0.1
   Isotropic
   E=1e+07   # Young's modulus
   nu=0.35   # Poisson's ratio
End

MATERIAL 1000
   density=0.1e-5
   Isotropic
   E=1e+09
   nu=0.35
End