text: import numpy as np
  from structsolve import lb
  import matplotlib
  
  from panels import Shell
  from panels.plot_shell import plot_shell
  
  
  def test_lb_orthotropic():
      #NOTE ssss boundary conditions by default
      s = Shell()
      s.m = 12
      s.n = 12
      s.stack = [0, 90, -45, +45, +45, -45, 90, 0]
      s.plyt = 0.125e-3
      s.laminaprop = (142.5e9, 8.7e9, 0.28, 5.1e9, 5.1e9, 5.1e9)
      s.model = 'cylshell_clpt_donnell_bardell'
      s.a = 2.
      s.b = 1.
      # radius
      s.r = 2.
  
      # compression
      s.Nxx = -1
      # shear
      s.Nxy = -1
  
      eigvals, eigvecs = lb(s.calc_kC(), s.calc_kG(), silent=True)
      plot_shell(s, eigvecs[:, 0], vec='w')
  