material Ar real
stress  linear
  modulus  0.00025
  possions_ratio 0.25
end
mass_density
body_force
end

material cubic real
stress  cubic
  c11  0.00030
  c12  0.00010
  c44  0.00010
end
mass_density
body_force
end

material damped real
stress  damped_cubic
  c11  0.00030
  c12  0.00010
  c44  0.00010
  gamma 0.1
end
mass_density
body_force
end
