*HEADING : EIGENVALUE ANALYSIS OF AN UNCONSTRAINED PATCH OF ELEMENTS [S8R5] *PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO *NODE,NSET=ALL 10,0,0 20,.24,0. 30,.24,.12 40,0.,.12 50,.12,0. 60,.24,.06 70,.12,.12 80,.0,.06 102,.04,.02 104,.18,.03 204,.16,.08 202,.08,.08 *NGEN,NSET=ALL 102,104 202,204 102,202,50 104,204,50 10,102,46 40,202,81 30,204,87 20,104,42 10,40,15 *ELEMENT,TYPE=S8R5, ELSET=EALL 1,10,20,104,102,50,62,103,56 2,10,102,202,40,56,152,121,80 3,102,104,204,202,103,154,203,152 4,104,20,30,204,62,60,117,154 5,202,204,30,40,203,117,70,121 *SHELL SECTION,MATERIAL=A1, ELSET=EALL .001, *MATERIAL,NAME=A1 *ELASTIC,TYPE=ISOTROPIC 1.E6,.25 *DENSITY 7.5E-4, *NSET,NSET=SIDES,GENERATE 10,80,10 *STEP *FREQUENCY, eigensolver=lanczos, SIM=NO 8, , ,-1.E5 *OUTPUT,HISTORY,FREQUENCY=1 *MODAL OUTPUT *END STEP