*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED MESH  [SPRING1, SPRING2, USER]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*RESTART,WRITE,FREQ=999
*USER ELEMENT, NODES=2, TYPE=U1, LINEAR
 1, 
*MATRIX, TYPE=MASS
 1.0, 
 0.0, 2.0
*NODE
 101, 
 102, 
*ELEMENT,TYPE=SPRING1,ELSET=SPRING1
 1, 101
 2, 102
*ELEMENT,TYPE=SPRING2,ELSET=SPRING2
 3, 101,102
*ELEMENT,TYPE=U1,ELSET=M1
 101, 101, 102
*SPRING,ELSET=SPRING1
 1, 
 1.0, 
*SPRING,ELSET=SPRING2
 1,1
 1.0, 
*ELSET,ELSET=SPR
SPRING1,SPRING2
*UEL PROPERTY, ELSET=M1, ALPHA=0.0, BETA=0.0
*STEP
*FREQUENCY, eigensolver=lanczos, SIM=NO
 8, , ,-1.E7 
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*OUTPUT,FIELD
*ELEMENT OUTPUT,ELSET=SPR
ELEN,
*END STEP