*HEADING
EC3KEFE1: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED 1-ELEMENT MESH  [C3D20E]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE
 1,0.,0.,0.
 3,7.,0.,0.
19,0.,7.,0.
 21,7.,7.,0.
 7,0.,0.,-7.
 9,7.,0.,-7.
25,0.,7.,-7.
 27,7.,7.,-7.
*NGEN,NSET=ALL
 1,3
 1,7,3
 3,9,3
 7,9
 1,19,9
 3,21,9
 7,25,9
 9,27,9
 19,25,3
 21,27,3
 19,21
 25,27
*ELEMENT,TYPE=C3D20E, ELSET=EALL
 1,1,3,9,7,19,21,27,25,2,6,8,4,20,24,26,
        22,10,12,18,16
*SOLID SECTION,MATERIAL=A1, ELSET=EALL
*MATERIAL,NAME=A1
*ELASTIC
  3.E+6,0.3
*PIEZOELECTRIC,TYPE=S
15.08,-5.207,-5.207,0.,0.,0.,0.,0.
0.,12.710,0.,0.,0.,0.,0.,0.,
12.710,0.
*DIELECTRIC,TYPE=ISO
5.872E-9, 
*DENSITY
7.5E-4, 
*nset,nset=nout
4,6,10,12,16,18,22,24
*STEP,PERTURBATION
FIRST STEP RESTRAINS ALL EPOT, COMPARE WITH C3D2011 RESULTS
*FREQUENCY, eigensolver=lanczos, SIM=NO
11, , ,-1.E7
*output,field, frequency=0
*BOUNDARY
ALL,9
*END STEP
*STEP,PERTURBATION
SECOND STEP RELEASES ALL BUT ONE EPOT
*FREQUENCY, eigensolver=lanczos, SIM=NO
19, , ,-1.E7
*BOUNDARY
1,9
*output, field, mode list
8,9
*element output
S,E,EPG
*node output,nset=nout
U,EPOT
*output, history, frequency=0
*END STEP