*Node
*Element, type=CPE4, elset=one
** Region: (Secn:Picked)
*Elset, elset=I1, generate
*Solid Section, elset=I1, material=Elas
1.,
*Material, name=Elas
*Density
70.,
*Elastic
 1e+08,0.
*step
*frequency,eigen=lanc
42,
*boundary
1,1,2
5,1,2
21,1,2
25,1,2
*node print
u,
*end step
*STEP
*substructure generate, type=z1, overwrite,
recovery matrix=yes, mass matrix=yes,
grav=yes,libr=lib_grav_solid2d
*RETAINED NODAL DOFS,sorted=no
*Retained Eigenmodes,generate
*substructure matrix output, stiffness=yes,
mass=yes, recovery=yes,grav=yes, file=lib_grav_solid2d
*END STEP