r5.01.03 Modal parameters and the norm of eigenvectors

Summary:

In this document, we describe:

the different possibilities in*Code_Aster to standardize the specific modes,

• the important modal parameters associated with natural modes.

• 1. Definition of the eigenvalue problem
  • 1.1. Generalities
  • 1.2. Generalized problem
  • 1.3. Quadratic problem
• 2. Generalized Problem Eigenmode Standard
  • 2.1. Components of a clean mode
  • 2.2. Euclidean norm
  • 2.3. Standard « largest component to 1 »
  • 2.4. Standard mass or generalized unit stiffness
• 3. Eigenmode norm of the quadratic problem
  • 3.1. Euclidean norms and « largest component at 1 »
  • 3.2. Standard mass or generalized unit stiffness
• 4. Associated modal parameters for the generalized problem
  • 4.1. Generalized quantities
  • 4.2. Effective modal masses and unit effective modal masses
  • 4.3. Factors of participation
  • 4.4. Unit displacement vector
  • 4.5. Special case of participation factors on modes that are themselves expressed in generalized coordinates
• 5. Associated modal parameters for the quadratic problem
• 6. Bibliography
• 7. Description of document versions