!EIGEN¶
Parameter settings for modal analysis
Parameters¶
None
** 2nd line and later **
| Variable name | Attribute | Description |
|---|---|---|
| NSET | I | Number of eigenvalues |
| LCZTOL | R | Tolerance (default: 1.0e-8) |
| LCZMAX | I | Maximum number of iterations (default: 60) |
| SIGMA | R | Shift value \(\sigma\) (default: 0.01) |
Example¶
Normally, SIGMA does not need to be changed from its default value of 0.01. However, it may need to be changed when performing a free-free modal analysis (= modal analysis without constraint conditions). If a free-free modal analysis is performed and an eigenvalue solution at 0 Hz appears, increasing SIGMA to a value greater than 0.01 (for example, 1.0) may resolve the issue.