*Heading
 S4R Elements
*Node
*Element, type=S4R
*Elset, elset=I1, generate
*Shell Section, elset=I1, material=Elas
0.5, 5
*Material, name=Elas
*Density
40
*Elastic
 1e+08,0.
** ----------------------------------------------------------------
*step
*frequency,eigen=lanc
20,
*boundary
1,1,6
3,1,6
13,1,6
15,1,6
*end step
*STEP
*substructure generate, type=z1, overwrite,
recovery matrix=yes, mass matrix=yes,
libr=lib_smdef_shell3D
*RETAINED NODAL DOFS,sorted=no
*Retained Eigenmodes,generate
*substructure matrix output, stiffness=yes,
mass=yes, recovery=yes, file=lib_smdef_shell3D
*END STEP