Hi, I have a question regarding CMS analysis in ANSYS Workbench 14.0. I really hope that one of you experts out there can/is willing to help me. I've tried normal substructuring (Guyan) and obtained the expected results in a modal analysis. Now, since the Guyan reduction yields significant deviations for most eigenmodes, I would like to try CMS. I've chosen a simple system, namely a 3-element cantilever beam: |------o------o------o I want to find the eigenmodes for this full model system by condensating the midmost element to a superelement, i.e. obtaining: |------o SE o------o The two midnodes are defined as remote points. I have done the procedure in analogy to the Guyan reduction, i.e. first I have generated the superelement. This is done in a separate analysis on the basis of only the midmost element (the one transformed to superelement): o------o The two nodes are defined as remote points in the model. The generation command is (partially copied from a tutorial): /FILNAME, BEAM2 /SOLU /COM NSEL, S, NODE, 1001 , N1 NSEL, A, NODE, 1002 , N2 M, ALL, ALL ALLSEL, ALL CMSEL, ALL NUM_MODES = 100 /SOLU ANTYPE, SUBSTR SEOPT, BEAM2, 2 CMSOPT, FIX, NUM_MODES, 0, 100000 ESLN, S SOLVE FINISH SAVE Strangely, this doesn't result in an error as it did when using Guyan reduction (another command of course). But it generates a .sub file I've tried to use in an analysis of the reduced model (the one with the superelement in the middle). The usage command is: /PREP7 ET,500,MATRIX50 TYPE,500 MAT,1 SE,BEAM2 FINISH /SOLU This command is taken from my Guyan reduction procedure. The analysis goes through, but I obtain completely wrong eigenfrequencies. Can anyone tell me where my error(s) is/are? It would be highly appreciated. Kind regards, Martin Ulriksen Student in structural engineering, Aalborg University, Esbjerg, Denmark.