*HEADING
360 DEGREES MODEL CORRESPONDING TO SINGLE B31 ELEMENT
*PREPRINT, ECHO=YES, MODEL=YES, HISTORY=YES
*NODE,NSET=NALL
1, 35.355339, 0, 35.355339
2, 0,        50, 0
3,-35.355339, 0, -35.355339
4, 0,       -50, 0
*ELEMENT,TYPE=B31, ELSET=EALL
1, 1, 2
2, 2, 3
3, 3, 4
4, 4, 1
*BEAM SECTION,SECTION=PIPE,MATERIAL=MAT, ELSET=EALL
10.,1.
*MATERIAL,NAME=MAT
*ELASTIC
10E8,0.3
*DENSITY
100
*STEP
*FREQUENCY,EIGENSOLVER=LANCZOS, SIM=NO
14,,,-1,2,3
*OUTPUT,FIELD, FREQUENCY=0
*END STEP