| E5041 | WARNING: E5041 | CHECK FLEXIBLE EIGENVALUE THRESHOLD FREQUENCY SETTING |
| Cause: | The EIGENFLEXFREQ model parameter was incorrectly set. EIGENFLEXFREQ specifies the threshold frequency for a mode to be considered flexible in a normal modes or modal response analysis. A rigid body mode was detected at or beyond the specified frequency. This may indicate an incorrect EIGENFLEXFREQ setting, a problem with the accuracy of the eigensolution, or a problem in the model. Rigid-body modes are zero-energy modes with the first flexible mode clearly identifiable by a significant jump in frequency and strain energy. | |
| Action: | Set the value of EIGENFLEXFREQ to the lowest expected flexible mode frequency in cycles per second. If no rigid-body modes were expected (i.e., the model is full constrained), a mechanism may be present. Examine the rigid-body modes to identify the problem area of the model. Also, check for an excessive extraction error measure or orthogonality loss in the rigid-body modes or first few flexible modes. See messages E5052 and E5053 for more information. | |
| Remarks: | See Autodesk Nastran Reference Guide, Section 5, Parameters, for more information. |