- Enter the ANSYS solution processor.
Command(s):/SOLU
GUI: Main Menu> Solution - Specify the analysis type.
Command(s):ANTYPE,BUCKLE
GUI: Main Menu> Solution> Analysis Type> New Analysis
NoteRestarts are not valid in an eigenvalue buckling analysis.NoteWhen you specify an eigenvalue buckling analysis, a Solution menu that is appropri-
at e for buckling analyses appears. The Solution menu will be either "abridged" or
"unabridged", depending on the actions you took prior to this step in your ANSYS
session. The abridged menu contains only those solution options that are valid and/or
recommended for buckling analyses. If you are on the abridged Solution menu and
you want to access other solution options (that is, solution options that are valid for
you to use, but their use may not be encouraged for this type of analysis), select the
Unabridged Menu option from the Solution menu. For details, see Using Abridged
Solution Menus in the Basic Analysis Guide.- Specify analysis options.
Command(s):BUCOPT,Method,NMODE,SHIFT,LDMULTE,RangeKey
GUI: Main Menu> Solution> Analysis Type> Analysis Options
Regardless of whether you use the command or GUI method, you can specify values for these
options:- For Method, specify the eigenvalue extraction method. The methods available for buckling are
Block Lanczos and Subspace Iteration. Both methods use the full system matrices. See Eigenvalue
and Eigenvector Extraction in the Mechanical APDL Theory Reference for more information on these
two methods. - For NMODE, specify the number of buckling modes (i.e., eigenvalues or load multipliers) to be
extracted. This argument defaults to one, which is usually sufficient for eigenvalue buckling. We
recommend that you request an additional few modes beyond what is needed in order to enhance
the accuracy of the final solution. - For SHIFT, specify the initial shift point about which the buckling modes are calculated (defaults
to 0.0).When RangeKey is set to RANGE,SHIFT is the lower end of the load multiplier range
of interest. Modifying the shift point can be helpful when numerical problems are encountered. - For LDMULTE, specify the boundary of the load multiplier range of interest (defaults to ∞). When
RangeKey is set to CENTER,LDMULTE is used to determine the lower and upper ends of the
load multiplier range of interest. When RangeKey is set to RANGE, the LDMULTE value is the
upper end of the load multiplier range of interest.
Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential informationBuckling Analysis