*HEADING : EIGENVALUE ANALYSIS OF AN UNCONSTRAINED 1-ELEMENT MESH [MCL9] *NODE,NSET=NALL 1,1.,0.,0. 2,0.707106781,0.707106781,0. 3,0.,1.,0. 4,1.,0.,1. 5,0.707106781,0.707106781,1. 6,0.,1.,1. 7,1.,0.,0.5 8,0.707106781,0.707106781,0.5 9,0.,1.,0.5 *ELEMENT,TYPE=MCL9,ELSET=ONE 1,1,4,6,3,7,5,9,2,8 *MEMBRANE SECTION,ELSET=ONE,MATERIAL=MONE 0.1 *MATERIAL,NAME=MONE *ELASTIC 3.E6,.3 *DENSITY 7.5E-4, *STEP *FREQUENCY, EIGENSOLVER=LANCZOS, SIM=NO 12, , ,-1.E7 *OUTPUT,HISTORY,FREQUENCY=1 *MODAL OUTPUT *EL PRINT S, E, *END STEP