*HEADING : EIGENVALUE ANALYSIS OF AN UNCONSTRAINED PATCH OF ELEMENTS [CPE4IH] *PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO *NODE 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 102,104 202,204 102,202,50 104,204,50 10,102,46 40,202,81 30,204,87 20,104,42 *ELEMENT,TYPE=CPE4IH, ELSET=EALL 1,10,20,104,102 2,10,102,202,40 3,102,104,204,202 4,104,20,30,204 5,202,204,30,40 *SOLID 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 7, , ,-1.E7 *MODAL FILE ** *OUTPUT,HISTORY,FREQUENCY=1 *MODAL OUTPUT ** *CONTROLS,PARAMETERS=FIELD 1.E-14, 1., 10000. , , 1.E-12 ** *END STEP *STEP,NLGEOM *STATIC *DLOAD 1, P1, -10000. 2, P4, -10000. 4, P2, -10000. 5, P3, -10000. *BOUNDARY 10,1,2 20,2 *EL PRINT,FREQ=0 *NODE PRINT U,RF *END STEP *STEP,NLGEOM *FREQUENCY, eigensolver=lanczos, SIM=NO 7, , , -1.E+7 *MODAL FILE *OUTPUT,HISTORY,FREQUENCY=1 *MODAL OUTPUT *EL PRINT,FREQ=0 *NODE PRINT,FREQ=0 *BOUNDARY,OP=NEW *END STEP