*HEADING
 TEST OF LINEAR USER ELEMENTS
*NODE,NSET=PR
1,
6, 2.
*NGEN,NSET=N1
1,6
*ELEMENT,TYPE=T3D2
1,1,2
*ELGEN,ELSET=TRUSS
1,5
*SOLID SECTION,ELSET=TRUSS,MATERIAL=S1
0.002, 
*MATERIAL,NAME=S1
*ELASTIC
2.1E11,0.3
*DENSITY
7200., 
*NODE,NSET=PR
101,
106,2.
*NGEN,NSET=N2
101,106
*USER ELEMENT,NODES=2,TYPE=U1001,LINEAR,UNSYMM
1,2,3
*MATRIX,TYPE=STIFFNESS
 1.05E9, 0.    , 0.    ,-1.05E9
 0.    , 0.
**
 0.    , 0.    , 0.    , 0.
 0.    , 0.
**
 0.    ,       , 0.0   , 0.
 0.    , 0.
**
-1.05E9, 0.    , 0.    , 1.05E9
 0.    , 0.
**
 0.    , 0.    , 0.    , 0.
 0.    , 0.
**
 0.    , 0.    , 0.    , 0.
 0.    , 0.0
*MATRIX,TYPE=MASS
 2.88 , 0.   , 0.   , 0.
 0.   , 0. 
**
 0.   , 2.88 , 0.   , 0.
 0.   , 0.
**
 0.   , 0.   , 2.88 , 0.
 0.   , 0.
**
 0.   , 0.   , 0.   , 2.88
 0.   , 0.
**
 0.   , 0.   , 0.   , 0.
 2.88 , 0.
**
 0.   , 0.   , 0.   , 0.
 0.   , 2.88
*ELEMENT,TYPE=U1001
101 , 101, 102
*ELGEN,ELSET=UTRUSS
101 , 5
*UEL PROPERTY,ELSET=UTRUSS
*BOUNDARY
N1,2,3
N2,2,3
**
*STEP,PERTURBATION
*STATIC
*BOUNDARY
1,1
101,1
*CLOAD
  6, 1, 5.
106, 1, 5.
*EL PRINT,ELSET=TRUSS,SUMMARY=NO
S,E
ELEN, 
*EL FILE
NFORC, 
*ENERGY PRINT
*ENERGY FILE
*NODE FILE,NSET=PR
U,RF
*END STEP
**
*STEP,PERTURBATION
Frequency extraction for truss elements only
*FREQUENCY, eigensolver=lanczos, SIM=NO
6, , 
*BOUNDARY
N2,1
1,1
*NODE PRINT,SUMMARY=NO
U,RF
*MODAL FILE
*END STEP
**
*STEP,PERTURBATION
Frequency extraction for user elements only
*FREQUENCY, eigensolver=lanczos, SIM=NO
6, , 
*BOUNDARY
N1,1
101,1
*NODE PRINT,SUMMARY=NO
U,RF
*MODAL FILE
*END STEP